Sexual perversion is sexual perversion. Legitimizing one opens the door to legitimizing the other.
No, it's reasonable thinking, since (if you check in scripter's links above and my reference to them) a MUCH larger perecentage of child molestations are committed by homosexuals than by heterosexuals. I don't mean the majority of molestations are same sex, but the numbers are roughly one third (depending on the study) and homosexuals are only about 2% if the population.