Ok, I've only read about 1/3 of your post and already want to say "YOU HAVE NOTHING TO WORRY ABOUT!" but let me continue reading....
Ok, to start, these drooling guys I am SURE are jealous of you, so don't let your confidence be down. She is interested in you, if not romantically (yet) at least intellectually, which is a good start to romantically, so give it time. But, time will not make it happen alone, you will have to (as said by other posters) make some attempt to do something with her. I agree with the idea to go watch her perform.
Perhaps introduce movies into your conversation, ones you haven't seen. Inevitably, ones in the theater will come up and she is bound to say one she wants to see. If you feel right about it, ask he to go with you, if not ask her anyway but with some other friends as well so it is not to intimidating like a date. Maybe bring her and/or friends back to your house, and if you wanna get cunning, have your friends get in on the plan and have them all leave your house to give you guys some alone time. That will get you two past the "hanging out with each other out of school" stage. After that, you are home free to pursue hanging out with her again, especially on your own.
Of course there are plenty of more ways to go about this, the movie thing was just the simplest example I could think of.
Whatever you do though, be confident, because after all, if you like this girl, then doing ANYTHING with her (friend or boyfriend) is good, so enjoy it. But flirting with her can definitely help. You seem to have already gotten past the hard stage, meeting her. Just take everything you already know and apply it to her. She wants to feel special, so make her feel that way. But if she doesn't play back, don't be discouraged, it only means she is not where you are yet mentally (unless of course she point blank tells you otherwise).