Just my opinion; You have an antenna problem that can be solved with a different antenna or different antenna orientation/placement.
1. almost all antennas are directioal to some extent.
2. Xmitting on 2 antennas adds more problems than it solves and gets complicated.
3.BCI and TVI problems can be minimized or eliminated by antenna placement, Ferite beads etc.
 4, You need to determine if the exact cause of the BCI/TVI. It is unusual with cable and satelite tv for the problem to be CAUSED by your transmitter. Just because you are heard on a BC/TV receiver does not mean that it is your fault. If the problem is in the BC/TV equipment that is where the fix is most effective. Don W8PTB

I could be wrong but I think Dave may have assumed that you were asking what power to drive the amp with. You realy want to know if 100 watts will hurt it in bypass. (amp turned off). I have been running 100 watts in bypass for several years now and the amp still works fin ewhen I turn it on. 73 WD8PTB

Yes; especialy if you want to work dx and also under marginal conditions. 73 WD8PTB

I have the 552g (6m) and I run 100w thru it ( amp is off) much of the time. As mentioned previously you do have to turn the power down when you use the amp. 73 WD8PTB

I would measure at the shack. The coax can act as a transformer and change the aparent SWR. Your presence at the antenna when you measure can also change the SWR. Your goal is to get the SWR at the shack reasonable so that you can radiate effectivly. At 160m coax loss will be negligable at any reasonable SWR.
  An inverted L is a vertical antenna so you need radials and they will also change the SWR at the shack.  If you use raised radials 2 resonant would be the minimum, 3 or 4 would be better, and with 6 you have reached the point of diminishing returns for efficiency.. With ground radials you need 10 or 12 minimum for resonable efficiency but they do not have to be resonant and can be zig zagged to keep in your property.   73 WD8PTB

Mine got abought 600 cw, 700 to 750 ssb. With 572b's I got 800 ssb. (grid current was less with 572's so I could drive it higher).
   The power supply is the same for the 811 and 811H. If you put 572'bs in the 811 you might get almost as much out as you would with the 811h because the tubes are no longer the limit.  73 WD8PTB

the touch switches are notorious for this. You will also find they produce RF interference. Mine put birdies on 160m. Junk the touch switch. 73 WD8PTB

I agree get the pro. No display problems and IF DSP.
 I have a 756p and a 756pIII. The PIII is better on 6m, has a adjustable NB, and has better recieve specs.
   73 WD8PTB

I agree get the pro. No display problems and IF DSP.
 I have a 756p and a 756pIII. The PIII is better on 6m, has a adjustable NB, and has better recieve specs.
   73 WD8PTB

My vote is for telephone lines. Back in the dialup days I had two modems fryed by lightning on the phone line.
   If you leave your antennas hooked up to your radio during a thunderstorm you will most likely have trouble eventualy.
 Power lines are fairly well protected by the power company but still can cause problems.
   During a thunderstorm the safest place for your radio is in the original box in the closet, Next safest is in the operating position with the antenna and power disconeccted.  WD8PTB

I'm an icom guy so I say proIII but... For all out recieve specs the K3 is the winner even beating the Orion. You will have to wait 4 months for the K3. On paper the recieve on the Orion and K3 are better but it depends on how you operate if you would see any difference. If you rag chew with your buddies almost any radio will work just fine. If you are a serious contester or DXer you need a better radio. If you operate cw technicaly you need a better radio than you do on ssb. Ten Tec caters to the cw guys. (qsk etc)
 73 WD8PTB

the radials do not have to be copper. I use aluminum electric fence wire. Some say that the soil will eat it up but I have had no problem with my soil.( NW Ohio) WD8PTB

Dipoles are normaly better for close contacts, Inv L for DX. There are exceptiions.  WD8PTB

You need radials; 12 min preferably 20 or more. If you tune by adjusting the lenth of the L you should get under 1.5 to 1 swr without capacitors. Center conductor of coax goes to L , sheild goes to radials. If radials are on or in the ground they do not need to be resonant and should be as long as possible in each direction. ( up to 1/4 wave) 73 WD8PTB

If you are the original owner Icom may still honor the waranty. ( they did for my 746pro 3 years after purchase because it was a known problem)Call Berghardt and ask. They are a otherized Icom repair center.  WD8PTB