Mark,
You ask some good (but, not "simple") questions regarding the FCC rules, and operating practices....power output; abusive/profane language....(and, although you didn't specifically mention it, our transmit spectral purity)...and, while there might not actually be 100% definitive answers (with precise numbers) to them all, there are some answers that will get you, both the straight scoop (real-world answers) and the "official" (legal) answers!

Relatively new to this hobby - just passed my General and studying for the Extra -
When the FCC says per CFR ยง 97.313 Transmitter power standards. (a) An amateur station must use the minimum transmitter power necessary to carry out the desired communications - does anyone besides those doing QRP actually adjust power up and down to follow that or if you've got 100W or 1500W you just park it there?
1) Let's hit the easy one first....FCC Part 97.313, power output standards.
97.313 Transmitter power standards.
(a) An amateur station must use the minimum transmitter power necessary to carry out the desired communications.
(b) No station may transmit with a transmitter power exceeding 1.5 kW PEP.
.......................
Mark, you ask:
...does anyone besides those doing QRP actually adjust power up and down to follow that or if you've got 100W or 1500W you just park it there?"
a) The short answer is, yes of course some of us do adjust power up/down as necessary.
b) The slightly longer answer is, yes of course some of us do adjust power up/down as necessary....but, I've never, ever had anyone ever comment that my signal was too strong, or ask me to reduce my power...and, unless someone was causing interference to others, I've never heard anyone ask anyone else to turn their power down....but, you DO hear some ask others to turn the power up!
{Three things you don't hear much on-the-air:
"I've just got too much money in the bank, and all this ham gear is such a bargain!" and/or
"I love these new YaeComWoodFlexCraft radios, they're all so perfect, reliable, and easy-peasy to program and use, and they are so low priced, I think I'll get a dozen spares!" and/or
"Your signal is too strong, please go QRP"....hi hi

}
c) The long answer is pretty darn long, and would involve delving into semantics, philosophy, ethics, etc., as well as ERP / EIRP (Effective Radiated Power / Effective Isotropic Radiated Power), so...
d) So, the better answer is: as above, yes of course some of us do adjust power up/down as necessary to carry out the desired communications.
And, in case some hams, or prospective hams, haven't copied it loud and clear, the FCC (and authorities in many other countries and sanctioned under international law) in writing rules for the Amateur Radio Service, quite purposely gives us wide latitude, and
specifically directs us to use "good engineering" and "good amateur practice" in abiding by those wide rules that they set out!
{just an example here....80m SSB in Florida...wintertime NVIS comms late at night, working stations 100 - 250 miles from me, there is no need for 1500+ watts, even with my "compromised" temporary antenna (my low, stealthy dipole), and most times I'd be barefoot at ~ 65 watts, but just a few hours earlier, working the guys in Europe on 80m SSB with my compromised antenna, then my amp would have been on and doing its job!
Now, move forward (or backward) in time ~ 6 months, now it's summertime, on 80m SSB in Florida, in the evenings (up to midnight, and even afterward) the distant/regional (and even worldwide) lightning static crashes raise the constant background noise 20 - 25db (or more) and the local crashes that come every couple of seconds are another 10 - 20db+ higher...so, what casual arm-chair copy we had months before, barefoot....now even with ~ 13 - 15db gain from our amps, we still don't have the wonderful S/N we had when the band was quiet...and, in addition to amps running all night, some guys (not myself) go looking for DSP "noise reduction" to make things a bit easier on the ears....(and when a DX station stops by for a chat, I'm usually looking for my headphones, 'cuz they are almost always already using their max power, just like we are in the summertime)...} If the "desired communications" is to be heard (in my example on 80m SSB) with decent S/N's so that we can have conversations, rather than
"sorry I only got about every third word....did you say your dog died, or was that your wife that died?"....then using our legal-limit power to overcome the high noise level, etc., does seem to fit in under "good amateur practice" and "good engineering".....BUT....(and, this is a big "but")
But, there are also other parts of the rules to consider in making the determination of whether your operating does actually fall under "good amateur practice" and "good engineering"....not the least of which are the prohibitions against, causing interference to other stations / "operations on adjacent frequencies", and occupying "more bandwidth than necessary for the information rate and emission type being transmitted, in accordance with good amateur practice." [NO, this doesn't mean that using an "amp" / running 1500 watts, causes interference, nope.....but, over-driving an amp DOES!
As does, hams using rigs with piss-poor transmit IMD / spectral purity, and then running them thru an amp, where the amp not only "amplifies" the already poor signal, but in many cases also adds more / contributes to the interference / IMD / clicks!
AND, lest we forget the hams using rigs with piss-poor transmit IMD / spectral purity, and then driving an amp (SS or tube) trying to get the thing's "advertised output" to show on the meter, but the amp manufacturer has taken advantage of the (unfortunately ignorant) new ham and is marketing an actual 500 - 600 watt output amp as a "800 watt amp"!
Or, how about oh so many hams (even many of my fellow contemporaries / old timers), that actually haven't a clue what IMD is! Yes, my rant could go on....but, that's for another day / another thread...]
97.307 Emission standards.
(a) No amateur station transmission shall occupy more bandwidth than necessary for the
information rate and emission type being transmitted, in accordance with good amateur practice.
(b) Emissions resulting from modulation must be confined to the band or segment available to the
control operator. Emissions outside the necessary bandwidth must not cause splatter or keyclick
interference to operations on adjacent frequencies.
....
Now, you're saying....whoa, wait a minute, I'm supposed to "use the minimum power needed, not interfere with other stations, AND not occupy more bandwidth than necessary"....all with "good engineering" and with "good amateur practice"?
I'm fairly certain some new hams, and/or those new to HF, and/or those recently upgraded to General or Extra Class, are shaking their heads and saying "Really? Really, those are the rules?" and "How am I supposed to know what 'good engineering' and 'good amateur practice' are?"
Ah, the answers to those questions are:
"yes, those are the rules (and, yes, most of us do try to abide by them)" and
"you learn about 'good engineering' and 'good amateur practice' by reading / studying for the exams (not by memorizing questions and answers), by learning from the existing base of amateur radio operators, and by using common courtesy / common sense (both on-the-air and when studying/learning off-the-air as well)."This IS the way the Amateur Radio Service works and/or works for most of us (or, at least the way it is supposed to work). And, as I wrote, this is not only the law under US code and of most other countries, but also codified under international law (ITU / UN)....and, not by chance it IS the VERY first "rule" in FCC Part 97.
Part 97.1
Basis and purpose.
The rules and regulations in this part are designed to provide an amateur radio service having a fundamental purpose as expressed in the following principles:
(a) Recognition and enhancement of the value of the amateur service to the public as a voluntary noncommercial communication service, particularly with respect to providing emergency communications.
(b) Continuation and extension of the amateur's proven ability to contribute to the advancement of the radio art.
(c) Encouragement and improvement of the amateur service through rules which provide for advancing skills in both the communication and technical phases of the art.
(d) Expansion of the existing reservoir within the amateur radio service of trained operators, technicians, and electronics experts.
(e) Continuation and extension of the amateur's unique ability to enhance international goodwill.
These very first rules, Part 97.1, are all too often overlooked by so many folks that "just want to get on the radio and talk to folks", that they forget there ARE other radio services for that purpose, but ham radio isn't one of them.
So, this being the real world of the 21st Century.....what happens when you have 1000's of people that "just want to get on the radio and talk to folks", all erroneously think that the Amateur Radio Service (ham radio) is this?
Well, I haven't personally listened to 7200, but I hear stories of it, and I have occasionally tuned up above 80m to the higher ~ 100khz or so of the 75m band....as well as I go back far enough to remember the zoo on 20m (was it 14.313 or .303?), the shootouts on 3895, etc. etc....so, Mark that is what we get....
2) The FCC can shut them down....but, it is up to us to "self-police"...record, make copious notes, and report all directly to the FCC...
Why can't the FCC shut down the bozos on 7.200?
<snip>
Is there any teeth in enforcement or not?
We get what we get there, because few newer hams have actually grasped what ham radio is...it is a "service" to our communities, to our country, to the whole world, where we are given great freedom to experiment / test / push the technical boundaries, etc., communicate in just about any mode / any way, with just about anyone in any country (even in outer space), etc...all with those 5 basic purposes as our goals / mission to accomplish...as laid out in Part 97.1
Now, I won't try and BS you, and even imply that every ham accomplishes all 5 of those goals every time they are on the air....but we do try, or at least try to do a few of them each time we operate, design something, build/test something, etc..
And, please understand that I'm not saying that anyone that doesn't care to try those goals ends up on 7200, no not at all! But, I am saying that those that DO try to adhere to those 5 basic purposes and try to accomplish them as often as they can ---- those guys/gals are NOT on 7200, or elsewhere on the bands causing trouble.
As for the FCC and enforcement....actually my personal contact with them in the past dozen or so years has been good! Sure that have scaled-back, but they have actually been adhering to the rules, and allowing us to use the freedom we have to expand/push technology, provide emerg comms, etc., and promote international goodwill....as long as we are using "good engineering" and "good amateur practice"....their enforcement approach is not a "hands off" approach, but is more of a "as long as they're using 'good engineering' and 'good amateur practice', we'll let them self-police". (which is quite a difference from the heavy-handed "all-knowing" FCC of my early days --- 1970's and up into the early 80's...)
FYI, those that wish to disagree with me, I accept that we all have different experiences...and, as I had an interference incident some 5 - 6 years ago, that showed me the FCC does care and that they are willing to help....a local ham was maliciously interfering my my 146.970 repeater (KA4WJA/R)....I didn't have the time to play games / track him down...but, I did record him and specifically told him that I was in contact with FCC (I was) and was sending the recordings to them (I did attach the audio files to an email, but never needed to send it)....I made telephone contact with the head honcho of the FCC, handling the SE US (and their chief of enforcement), this took me two phone calls (waited a half day)....they called me back and I explained the situation....and they said "record it...send the recordings to us...we will start the investigation and be in contact with some info/results within 30 days"....fact is, once the word got out that I really was talking to the FCC, the guy gave up and I never pursued if further....(but, just 2 years ago, I did pass on some info on FM broadcast....I passed info to a local broadcast engineer, who passed it along to the FCC....in regards to a "pirate / bootleg" FM station, I traced near Orlando...and, within two - three weeks the station was gone!)
So, again, I know some say the FCC doesn't care / won't enforce anything....but, that has not been my experience....so, if you feel something / someone on-the-air is truly objectionable, record it along with as much detail and technical info you can manage...and forward it to the FCC, and give it a month or so....I think you'll be surprised....(at least my personal experience says so...)
3) DX running "split"...
James, K0UA, explained things very well...
In listening to people trying to connect with a DX station last week, one gentleman the width of the country away from me kept yelling out his call sign every thirty seconds or so. I was trying to hear who the DX station was so I heard him go on for at least five minutes and he was booming. Is that acceptable behavior? I heard other weaker (to me) stations trying to make contact but nowhere near as insistent.
Acceptable? No...
But, it does happen....and, just like folks splattering, and/or hams not even grasping what our Amateur Radio service actually is....it happens because we [hams] have almost stopped teaching and learning (to/from our fellow hams)...
Again we get what we get, because we all seem to accept "less"....instead of demanding more from ourselves (personally/individually) and from our fellow hams, we simply accept less (you know, that attitude that "that's what the big dial is for"...we accept less = we get less)
Anyway, re-read James' post for the details on working "split".
https://www.eham.net/community/smf/index.php/topic,138052.msg1283782.html#msg12837824) I am also an offshore sailor....sailed my first Atlantic crossing > 40 years ago...
I used to sail offshore a good bit and really enjoyed the cruisers' nets. I'm now using a mag loop with a KX3 and I don't think my signal is getting out there. I've got a crank up tower and a KXPA 100W amp I plan on using when it warms up enough to sink anchors.
The KX3 is a nice radio, but you REALLY need a decent antenna!

[speaking of IMD...be careful with that KXPA-100....as its IMD specs, from ARRL Product Review tests, are not great...average, at best...
Elecraft KPXA-100 = 32/34/42/52 db(PEP) for 3rd/5th/7th/9th order products...and that's at a solid 13.8vdc....and, like most "100 watt" rigs, if you try to run it on "battery voltages" (12dvc - 12.8vdc), it gets worse...]
I know I wrote a lot here, and for what you posed (guessing with an assumption that it was a simple question?), perhaps more than you expected....but, I did want to actually answer your questions, not just throw some BS at you.

So, I do hope I helped some?
And, from one offshore sailor to another, Fair Winds!

Here are some pics, videos, and links....my boat, my offshore sailing, maritime HF radio, etc..
https://jerodisys.com/C470/470pix/4707820.htmhttps://www.youtube.com/user/captainjohn49/playlistshttps://jerodisys.com/C470/foto_bot.htmhttps://www.instagram.com/ka4wja_/https://www.qrz.com/db/KA4WJA73,
John, KA4WJA
And, while not a great shot, here is my current boat, in Horta, Faial, Azores in 2007...
https://jerodisys.com/C470/470pix/4707820.htm