you wont need to wait tho, but you should definetly xfer, it just adds more security, and ban his old account,
eventually he will wanna play again, and can simply recall his account on the phone with blizzard,
but when they tell him it is banned, he will need to fax in ID, and once he does that, he will get on and see no character,
then he cant do anything about it, would of been to long in my opinion, if there is a problem with your character blizzard wants to know asap,
and wont give his char back, i know from experience, i lost my warlock
good luck man