Personally I think the main problem is people getting their accounts hacked. And 90% of the time that's because players are reusing their SE username/password someplace that's been compromised. SE should force every player to use a Security Token, including mailing one with the boxed copy of the game. If they resolve that I think the problem will die down a bit when subscriptions kick in.

RMT have to level to 20 and do the main story line to be able to sell anything on the AH (which includes running 3 dungeons and a lot of running around). The only way around that is with their hacked accounts.

I think SE should prevent anyone without a GC from trading gil or even using the auction house. Getting to 20 isn't difficult, and you don't need the auction house till level 20. Dye is sold in vendors and there is nothing on the AH you absolutely have to have prior to level 20. All the gear you need till 20 is sold in vendors or given from quests. And the 15-20 dungeons drop gear.

I think doing that, with subscriptions active, will make RMT such a pita they won't be as thick.