InSearchofAnswers,
I have sympathy for your girl here. I mean, I know people who have been raped, and it definitely has a big affect on people, and I commend you as a guy for being able to be sympathetic about it, because a lot of guys just don't know or don't care...
And I don't think you should necessarily assume she would cheat on you; I think you're probably spot-on in thinking she does this kind of thing to try and maintain some kind of power balance with you. She doesn't want you to think you have too much power over her (which may even mean that, really, you mean more to her than you know... or not)
I don't think you need to make her feel bad about herself for her choices -for wanting to remain friends with exes, or for wanting to tell you about her history, say. That's really a personal choice thing. I've dated guys who were much more open about that kind of stuff than I was, and ultimately I just decided that if I trusted the person, that kind of stuff (being best friends with an ex, etc.) shouldn't bother me. I mean, people are people and friends are friends, and in a society with fewer taboos surrounding sex, hopefully they wouldn't be any less so just because you've had sex with them...
But I also agree with the other posters that say that she may not meet your needs, and you have as much right to break up with her for that. In fact, you're probably not helping her if you're visibly unhappy a lot -martyrdom in a relationship is generally not practical or healthy. I wouldn't necessarily think your way is better, or that everything she does is just because she's "messed up" from a traumatic experience -I think that's over-simplifying. But you might just say to her: "I do x, y, z for you because you matter to me. I need you to do x, y, z for me... and when you do v, w instead it hurts me. This relationship just isn't working for me. If we can't compromise on this issue, I think we're not compatible, and it would be best to end this relationship to allow us to search for more compatible people..." Something like that. Something very honest and straightforward, where she won't feel like you're blaming her or accusing her of being "broken" or something...
Make sense?