I don't have time to completely respond, however,:
if it were legalized, it would probably up the research on prevention/cure of std's/pregnancy (a way that people would not be like "OMFG you just killed a ooman lifey!" after 2 weeks of pregnancy:p
it would also cause an uproar in the ethics and morals of the general populous (no matter how stupid they are, there are still more of them) and it would open up opportunities for more people to cheat on their spouses, which would up divorce rate even more I'm sure
rapists (I'm not sure how you think child molesters will be benefitted from this unless you're suggesting that child labor laws be repealed....) would not be helped much since it's more of a powerless victim/fear issue that gets those people going (a lot of them anyway) and you'd have a small (maybe) decrease in sex crimes (though I'm sure lonely people would be interestingly broke)
good points otherwise though, for now