Mike had some interesting questions regarding his situation, and I've asked him if it's ok to discuss them here.
First off, let me just say that I like Mike. He strikes me as a person who's kind, thoughtful, and intelligent as well as idealistic. I have to admire his earnestness.
I'm only going to address some of these questions, and from my own personal non-expert perspective, obviously. I'm no authority on what's 'right,' but I can put forth my own philosophy, and I hope others will take the time out to give theirs, as well.
First of all, one can only speak in general terms about what women value, since women make up half the humans on earth, and every woman is unique. Naturally there are going to be some women out there that have tried their best to always do everything 'right' as Mike has, and would value that same dedication to making good choices. However, I don't know too many people who are so spot on with every single one of their choices, nor do I know too many people that think so deeply about every decision they make and how it will affect their futures. It's just not the way the majority of people operate and I believe it's very idealistic to expect that is how most people live their lives. For instance, I'm fairly sure that while Mike's girlfriend was allowing herself to be used in a sexual situation by some unsavory characters, she was not thinking about her future. I don't know her so I don't know what she actually was thinking, but I'd be willing to bet her future was the furthest thing from her mind.
I'm not sure what sorts of fantasies Mike is wistful about not partaking in when he had the chance in college, but what strikes me is that he talks a lot about boys using women, and has an issue with that. I feel using someone in an unkind fashion is a bad thing. (Getting a girl drunk and taking advantage, pretending to be interested in her emotionally when you're not, etc. etc.) But not every instance of casual sex can be put into the category of a man unkindly using a woman. Women certainly do use men for casual sex, too, and as I've said before, I really don't think there is anything wrong with having casual sex as long as both parties are on the same page about what's going on.
Since I don't know what Mike's fantasies are, I don't know whether he should pursue them or not , or even talk to her about them. But 24 is so young, and it's likely he'll have plenty of time to take care of them at some point, if they are the kind of fantasies one isn't participating in with their partner.
Help a brother out here, folks.