I perform at school alot and I have found that there are a lot of tricks that you can do without cards.
STS ... You probably have heard of it alot, but it is pretty much impromptu and might get you a little gig before holiday break.
Two dollar window ... Its money, everyone can relate to it, easy to do, not angle sensitive, hecklers have a really hard time if you do it right, and is allowed everywhere you go.
Hummingbird card, you can float alot of things with it and it doesnt have to be cards.
I hope I helped you a little bit on your school magic ... and, try and maybe get your teachers to let you do a little magic show or something instead of just watching a movie. Good luck man ... good luck
Just buy Bobos coin magic because they can't stop you from working with coins in school...STS is not at all impromtu and all of those effect you mentioned are gimmicked...If you want some great coin effects and impromptu effects you should definately get On the Spot by Gregory Wilson...