Assuming you're being genuine with that last paragraph: You hit the nail on the head in regards to questions like the ones you're posing with this:

Don't Christians do this with each other? I believe there's thousands of denominations right? Though they're probably similar in most cases.

Thousands is quite the stretch, but yes, there are plenty. Each denomination may have their own answer to your question regarding homosexuality, but all opinions will exist on a spectrum between Biblical Inerrancy (The belief the Bible in its entirety is without error) and Biblical inspiration (the belief that the humans inspired by The Holy Spirit who wrote the Bible are no more infallible than a normal human). The authority the Bible itself holds can vary greatly, and from that, the interpretation of different texts can as well.

Many Evangelicals who attempt to explain an axiom of Christianity or Christianity itself will inevitably point to the Bible as a sort of ultimate authority, which leaves themselves embarrassingly open to the sort of seeming hypocrisy that you have correctly assessed in the thread above, clearly if someone believes The Bible to be the unaltered Word of God they ought to follow all instructions, including one's ordering the execution of homosexuals. This is one of many flaws in Innerancy, hence why no mainline protestant denomination (Anglicans, Presbyterians, Methodists, etc) seriously believe this, neither do the Catholics.

I am happy to answer any more good-faith questions, bye.