I think you summarized this issue quite well.
However, Dean Hamer's research was flawed because he used only the mother's family tree to develop his research universe. Only gay men who had a gay uncle on the maternal side of their families we included. The paternal influence and straight siblings were excluded.
Evangelicals have rejected evolutionary theory based mostly on Genesis 1. Since the dawn of the industrial age and the increase in scientific knowledge the theory of evolution has become generally accepted as fact, when in reality it is nothing more than an unproven theory. You might like to join in on the discussions in the Science Forum where physics and other disciplines are under discussion. A proper understanding of physics alone can disprove evolution. We have a member who is very knowledgeable in this area.
As to the roots of homosexuality, there is an abundance of data that demonstrates the primary roots are psychological. This in no way eliminates a possible hormonal or “genetic” predisposition. But again, no empirical data has been published to show a genetic link other than personality. Some gay proponents appeal to animal studies that show rams have a genetic predisposition to homosexual behavior. What gay proponents do not share is the researchers opine that inbreeding is the cause.
Homosexuality is to complex a subject to reduce it to couple of paragraphs. So the question any active gay individual must answer for themselves is who is sovereign; man or God.