I logged on the forums with my recently banned (ingame banned, not forum banned) account and noticed you can still browse the remote AH with it and see what unbound items the chosen character has in bags/mailbox/bank. Buying/selling auctions gives a "Warcraft Remote subscription is required" error and it's not possible to add one on a banned account. Has someone gotten banned with an active remote subscription and tried this?
Looks to me buying/selling (and therefore being able to remove everything of worth off an account you don't have access to) might still work if you have a subscription unless it gets taken off.