"Why exactly?"
I understand that is a huge thread and no one expects you to read the whole thing, but I suggest you read at least some of the thread.
"Is it wrong to call anything a sin?"
When it hurts other, yes.
"It would seem logical that sin is sin, it really doesn't matter what one may think."
Blind, thoughtless adherence to a religious text is just downright stupid.
"If one believes in a god, then that originator of the Universe certainly has the right to call it like he see it ---- it really isn't an individual's call."
It certainly is not your place to dictate how "God" feels about homosexuals. You are not "God" nor do you speak for "God"; you have no idea how "God" feels about homosexuals. Maybe He made them for a reason, maybe "God" wants homosexuals around. Homosexuality is common and significant among several different species while homophobia only exist among humans.
Spreading calumnies about homosexuals because you think you know the mind of "God" is not only incredibility egotistical but rather brainless. How about you come up with a real reason to justify your own prejudice instead of abusing God's name.
" GOD may just ask, "Who do you think you are, and why do you imagine your values count for anything."
No, this is just what you are asking and you are just using God's name for effect. But ask yourself the same question: Why do come off acting like you can speak for "God'"? WhoTF are you?