The main things I recommend doing before changing your name: Unclaiming your plots on opprison/creative so you are able to re-claim with your new name. Remove any chest signs under your name (shop/private) For survival, I haven't seen many (if any) issues regarding loosing claims. But, it's better to be safe than sorry.
I'll go ahead and close this as it appears ypur question has been answered. Remember to do what was already stated by users above.