I don't see that you need "help," necessarily.
Sure, God isn't a trinity. Cool. Lots of people who believe in God believe he isn't a trinity.
Lots of people in lots of religions don't believe that Jesus is God, either. Cool.
Is disfellowshipping unscriptural? Probably not. Many horrible, inhumane things are scriptural; shunning may indeed be among them.
Does Jehovah tolerate immorality? Depends. Sometimes he does, when it's convenient for procreation and so forth. Incest didn't seem to bother him too much when Lot got drunk and slept with his daughters, if memory serves. But then, there's a lot of stuff Jehovah doesn't tolerate. Making fun of bald people, for example. If you're ten years old and you want to point out that a bald man is bald, better set some bear traps first.
See, some of this stuff just doesn't matter to anyone but you (I mean that in a good way) -- because the sort of "evidence" you're looking for will only be substantiated by faith. You'll make interpretations and come to conclusions and that's your right, but you won't find some scientific, object proof of your beliefs. Hence, faith. So believe whatever you think is best. Just remember that you can't empirically prove that you're right, and that's okay, so long as you don't get arrogant about whatever it is your faith does for you.
Dedalus