Luckily, I've haven't had the displeasure of playing many people who were both inexperienced and rude at the same time. One thing I do before playing someone I know or suspect is inexperienced is clarify en passant and castling BEFORE the game starts. Then, at the very least, we can both agree to simply not play with those two rules.
As for how to deal with someone who is (whether intentionally or not) cheating by moving your pieces around, I don't know what to do. Any countermeasure against that (notation, video taping the game, etc) seems a little excessive for a pickup game...
this is stupid. if i played someone like this i would end up punching them in the face