Considering that two years ago he blamed the abuse on the bad influence of the Vatican Concil and the "decay of morals"
When did he do that? He has been a champion of V2.
You are confusing doctrine with practices/rituals/policies. Doctrine is a teaching or belief based on the Church's understanding of an objective truth--the very nature of doctrine makes unchangeable as it is objective truth--you may disagree with that, but that's what the Church believes. Wheras, practices, rituals, and policies are not beliefs. Then, you have things like limbo, which is a theological theory that has neither been rejected or accepted as objectively true, they are theological developments that may never be accepted as true.
...sympathy with...many gay Christians...do not wish to be condemned on flimsy theological reasoning then those bigoted scumbags who apply Jesus teaching very selectively at best
And, you have that right, but that only tells us something about you and your beliefs and attitudes.
If these teachings are taken selectively, I also then must suppose that Paul got it wrong and his writings should be stricken from the canon of scripture?
Well, that is what the bishop of Rome claims
Not only him, but the Church Fathers, as well as a plain reading of scripture.
theological argument behind the papal institution is a bit lacking (...where does Jesus claim that the leader of his church has to be in Rome?).
I find that lacking. It being in Rome is incidental, it could have been anywhere. That's not the theological argument. The theological argument is in the person of Peter who, according to scripture, was told by Jesus that He would build His Church on Peter and to whom the "keys" to kingdom of God were given. In scripture, we also see how the early Church defers to Peter when conflict arises.
.it's nice to be able to ask an expert! :)
I'll see if I can get you in touch with one :) .