Well, I don’t think the Bible says that gays can’t preach. I think it does say that those who practice homosexual behavior are going to hell. So you might argue that a gay could preach, on his way to hell. And a straight women cannot preach, though she is on her way to Heaven. But I am not sure that makes sense.
As to limiting scripture to what Christ said, you are doing just that, limiting scripture. You may as well just use Christ’s quotes. I would make for a much shorter Bible.
I think the respector of person thing may deal with the fact that we are all sinners and none better than others in that sense. But that does not mean that people are equal and it does not mean that all are equally qualified for various positions. I think the Bible also bears that out.
But again, to dismiss the stated qualifications of a preacher/pastor you have to say that all of the Bible is not correct because Paul gave those qualifications in on uncertain terms. If you base your argument on that then the discussion must turn to – is the Bible inerrent?