You bring up a good point regarding unwed motherhood vs. abortion. It is no small feat that the show allowed the child to be born. Additionally, the shows I've seen rarely revolved around the issues that concern Colson; the sex issues were always in the background to a degree. Compare that with Seinfeld's "The Contest" (possibly one of the funniest TV episodes ever), and Friends is pretty tame.
As for the preteen audience, that's the parents' responsibility.
Interesting point.