Oh yeah, of course homosexuality existed. But homosexuality back then was interpreted very differently than modern concepts of homosexuality.
But interpretation of the Bible can be done in a reasonable way and then in an unreasonable way IMHO. Again I consider it a book not a living spiritual document so that's my bias. But lets use a different example.
Say you do research back on the experience of slaves in the United States and you find that many of the slave owners basically picked strong slaves and broke up families and so when the slaves that lived together and recoupled and had children, their strong genetic make up created a situation where African Americans were stronger and more physically capable than their white counterparts. It's one thing to say that this is what resulted but quite another to try to go back and put intention into it that didn't exist at the time.
So for example it would be like going back and saying slave owners deliberately did this so African Americans would become great athletes in the future. And that if you think about it they were actually being supportive of future generations of African Americans in the US.
(BTW I know this is filled with politically incorrect crap I don't believe this but I'm using an outrageous example to show how it comes across)
You can't go backwards in history and rewrite the script. Religious tomes are the only ones that people feel justified in creating a "foresight" or "intention" in the writing because it is guided by the "hand of God" the "all knowing" etc etc etc.
For those of us who see the Bible as a historical document, there is no way to reinterpret the information and statements without giving the writers waaaaaaaaaay too much credit. And technically God did not say any of the apostles or writers had any sort of divine insight. So IMO we should only interpret what they wrote in the way they wrote it and not try to give it more weight than it deserves.
Paul might have made some statements that to a modern eye could be viewed in a different way today but back then there is no doubting what he meant.
ETA I'm not that big on Paul so I'm not trashing your thesis. Just pointing out a pet peeve of mine.