I'm an observer. Go to the Walter's Museum of PAthology. You will see humans that have been born with all sorts of "oddities" - to say the least.
To think that some males weren't born with extreme feminine desires or that females are born with essentially "male brains"...is to deny reality.
Most males have a varying degree of femininity (except Ted Nugent). And most females have some "maleness". Occasionally, these traits cross "some line" that tilts them toward the "wrong sex". It just is. I don't make the rules. God does. All I do is observe and report.
Your points are generally why developmental biologists ridicule developmental psychologists. (some don't even consider psychology a real science. Its just where you store those smart enough not to get an education degree but not smart enough for a real science degree)
The whole female behavior male behavior spectrum is an absurdity when it comes to sexual behavior. Homosexuality is recreational sex. period. It does NOTHING for society.
All the other "fluff" is irrelevant to the furtherance of society. Those same shrinks would say an unemployed between jobs father who stays home while looking for a job is exhibiting "female behavior" while that woman is doing "male behavior". So getting a hair cut at a salon is female behavior but a barber shop is male behavior.
There make be arguments for a "spectrum" when it comes to normal humans. However no matter how you slice it, homosexuality is always an abnormal behavior just like sex with animals or some other screwy sexual fetish.
Back at ya! Even members of the APA are now saying it's possible to leave the homosexual lifestyle: Sexual Orientation Change Is Possible— But Only Outside Of Therapy, Says APA Office Of Gay Concerns
Besides that, there is no scientific evidence anybody is born gay. If you think so, I'm more than interested in any article you can reference. You can't, but I had to make the offer.