I'm with Drifterwood, subgirrl, and petite on this. I stand by my original comment in this thread (post 2). There is a fundamental incompatibility in your relationship, uboat. If I were her, I'd be extremely offended by your letter, your attitude, and I'd get rid of you so fast you'd have friction burn and no memory.
You are self-righteous and condescending. "You are a smart individual, and I believe you know what is right and wrong in a relationship." You do know, do you not, that relationships come in many flavors. You don't like the same flavor she does. For the record, that doesn't make either of you wrong. It just makes you a bad fit. The very idea that you agree with the poster which suggested your girlfriend needs to be "put in her place" speaks volumes. Oh my God, out on your ass.
Let her go. You do not lover her, not the way she sees herself anyway. I, like petite do not respond well to a lack of trust. If you don't trust me, and I've not cheated on you, I immediately decide you've been cheating on me, and get rid of you based on that. Experience has taught me that only untrustworthy people mistrust without cause.
For what it's worth, I'm happily married two years now, and have been living with my man for three years following a long distance relationship (2000 miles, and then 225 miles). The way we saw it, neither of us entered this relationship to shake up each other's lives. We are drawn to each other, as we are. He knows he can't come between me and my friends now, and he never tried to. Like your girlfriend, I don't usually get along with other women, so the vast majority of my friends are male. Most of them were here before he got to me, and if he chooses to leave, they'll be here when he's gone. He accepts them, they try to befriend him (as much as you befriend your friend's lover) and we have no trouble with this.
Here's the thing with people. You cannot (and should not endeavor to) change them. You find someone with whom you share values, mores, and if there's mutual attraction, you see what you can work out. You don't just hook up with a pretty face and a positive outlook, or you end up with what you have. Something doomed to waste your time. (That sounds harsh, and I apologize in advance for the harshness, but I see it as true, and do not write it to be mean.) You like a few things about this girl, but you don't like who she is, not really. She keeps telling you precisely that. You wrote that she says, "its part of my personality" or "its who i am" . Why can't you listen to her? If you can't accept her, why not let her be free to find someone who can? You say that you want to nurture her self esteem. Do you think telling her that her personality and values are wrong or immoral is a big boost to her self-image? Give me a break with that.