You explained who your roommate is, don't you wonder why he takes your things. Sounds to me like he doesn't really need them or does he? Is he short on cash to keep up his image or does he have a problem with stealing things? Maybe you will find your answer in those questions and I know you probably don't want to think about this but maybe your supposed to help him? By confronting him or by catching him and turning him in, help comes in many ways.
love and light