Genevieve,
1-If they think marriage means nothing, then at least they found someone who thinks likewise.
2-Those I know who had premarital sex (and especially those who had children before marriage) have had more marital problems than those who have married, waited to have sex, and waited to have children. These are all family members and friends--not just my insistence.
3-I doubt people having premarital sex think anything of divorce. Why would they? That's why they're having premarital sex. But if they were considering marriage, and they knew their partner had lived unmarried with other partners before, don't you think that would factor into the equation?
4-okay.
5-"definitely" is too strong a word, but I think it makes your point. However, marriage is in no way cookie cutter. Socially, it's a formal act that signifies two individuals' dedication to each other. Why would two people who really love each other not want that?
6-Those rising numbers scare me just as much as unwise early marriage scares me. 
7-I think here I'd have to say "lay off," your hubris is showing through. In no way are these children screwed up. They miss the opportunity to have the strength I know a traditional marriage brings, but by no means are they forsaken or without support. Single moms, broken families, unfortunate death of a parent, and yes, even unmarried parents--these are the things children live with every day and when these situations don't serve to weaken and bring despair, they strengthen and give these individuals resolve to do better and try harder. But it's not ideal.

My goal is not a mild happiness and respect. I want perfection. I won't make it now or in this life, but I want it. I'm trying to do what it takes to get it. And it takes a lot--a lot of hard work, a lot of praying, evaluating, and tireless trial and error. Some people don't want that. They don't want to work that hard for what they see as un-beneficial. They think they have better things to do. How could I judge poorly of them? Some days that's me. That's all of us. But I would want to encourage them to learn something better. People will live differently whether I like it or not; my main concern is whether I'm setting a worthy example or not.