i don't know that the name will change and post with all old posts. however, i do know that if it does and you change your signature as well, that the signauture will change with the old ones as well. so you should be able to be pretty well hidden if new name changes with old posts (which i suspects it does) because signature and avatar changes with old ones.

as far as letting ppl know it's you...post a post to the members here is the only way i can think of.

gl