Two corrections for the OP.

The thing is, you can't do that. You can't delete a thread that other members have posted in. You can move it, but only the admins can delete it. You can only delete a thread if no one else has posted in it. That doesn't apply to all sub-boards though. But like I said, you can always move the thread to one that allows deleting and do it there.

You won't get banned for using multiple accounts or enrolling them in the same signature/bounty campaign. If there is enough proof, you will get tagged but not banned. The forum has no rules about multi-accounting and the admins aren't monitoring what you do with them.