Some EU characters are accepted and some are not. Right now I'm working on a Darth Nihilus costume from the KOTOR II game and I still am not 100% sure if it will be accepted in the 501st or not and I am already a member!! When it comes to EU, it's a huge gray area until that costume/character is officially approved by the 501st. Best bet on trying to just become a memeber is to get a costume you saw in the movies, it's a sure fire way of getting in the 501st. Also V, after you get your TK done, if you have anymore issues with trying to get in the 501st, please send me a pm. We girls need to stick together.