A week most likely though you shouldn't do it if you're planning on it again.
Why would he even ask you to post for him if he knows it's against the rules?
im guessing we're going by badspot's code of laws, where you're banned for a week if you break a minor rule, and forever if you break a major rule, and if you break 5-6 minor rules and get banned for all of them, you'll get perma'd
He didn't know until after.I've only had one major on a different account, and one minor on this one.
Edit it out?
You're screwed.
I'm sure if Badspot understood you didn't know that it was an offence until after the point that you posted, and now you realize that you can't really post for banned users, I think you'll be fine.