DA - Frankly, its a standard issue. I dont see it as a bad thing that a girl isnt a virgin, and that seems to be the general view on this board. Nonetheless, its ignorant of *US* to tell you that you must believe what we do or you're a horrible person. As long as it doesnt concern us, we're not the ones to judge you (much in the same vein, hetrosexuals shouldnt try to stop gay marriage). You're not telling us how we should live our lives, just how you live yours and prefer the person you end up with live theirs. I think we should stop telling you to change your value system.
If you need someone who's only been with you, I can understand that, since you're keeping yourself for the girl you marry. Sacrifice on both parts. To answer your question about the virginity issue, someone early on said the right thing: how much can you trust this person? I was with a girl who I loved to death, but couldnt trust. The relationship was painful for me. If a girl cant be trusted, you shouldnt be with her regardless of virginity. But when it comes to finding out, the only person who really knows is her. And the only way of knowing is her being honest with you. Now ask yourself this: Is she likely to be honest with you?
(also, questions can be put in a roundabout way to get answers if you're willing to be patient - one question leading to another 2 days later, and so on until you can paint a clear picture. Sneaky though.)