Very good, very succinct analysis of sex and marriage. My hat's off to you.
I really like your thoughts about marriage. I also think people should marry at 18-25, it's healthier and easier that way. Cheaper, too (saving on infertility treatments, which may be necessary 10+ yrs later) :). I am saving all my money so that when my daughter turns 18, lack of money wouldn't stop her from marrying. I will do everything in my power to encourage her to marry early.