If I call/email nintendo in a formal way asking to be unbanned, does the HBC get removed?

I probably already know the answer, but I just want to be sure.

mmmm i think you have to get rid of the hbc before you can be unbanned

No, it doesn't get removed. It's just if you hack again and get banned, you're screwed. They don't remove HBC. And you don't have to either. It can be used for many other things besides hacking Mario Kart.