re: If homosexuals are “born that way”

Homosexuality is not genetic. It is an acquired/learned behavior closely associated with one's relationships to the opposite sex at an early age. I've discussed this with many gay or bi sexual men and there is a common theme of early relationship patterns. Most gay men will tell you they always felt awkward around women, while feeling very comfortable around men.
When a young person has bad interactions repeatedly with the opposite sex, they in turn avoid those contacts. Then later a line is crossed when comfort level turns sexual.