I don't think DGTL means DPL. it means DGTL as in DSTAR,P25,DMR and those would need a special rig.
most lists will show DPL as D072 or similar.
Not so sure. I have seen PL repeaters that do not list PL frequency in directory. Same can be true with DCS.
I always check the state repeater council to double check. most will post a repeater list of coordinated repeaters.
repeaterbook.com does a decent job. and repeaterbook.com DGTL = digital mode repeater.
And you are right not all lists are 100% correct. some machines get converted to DMR or another digital mode, some that were CSQ end up having pl turned on. but between the state coordination list and repeaterbook.com you can get at least 99% of the info.