1. How do you intend to get around the terms-of-use violations for most of these MMOs that explicitly state that buying in-game currency is forbidden? I honestly have only played WoW from that whole list, so I'm not much of a gamer myself, but I know that Blizzard at least is very aggressive in making these sorts of things difficult, or at least a bannable offense if caught. Especially for selling whole accounts.
As the owner of
https://ferroh.com/d3 , I can tell you that Blizzard does not appear to care whether you buy D3 gold.
The trade forum is filled with people trading gold for paypal, and I have never seen Blizzard delete such a thread.
The situation with WoW is a little different. Real money gold trading might change a bit when Blizzard adds gold to the RMAH (it's still not available there).
Well the reason why they have not implemented the D3 RMAH for gold yet is because of people that are already selling gold. I don't think they want to see the D3 gold at rock bottom prices. When they do after all the fees with blizzard(selling for paypal of course) its $1.12 per million for the seller and it costs $2.50 for the buyer.
So essentially cutting out the middleman in this case blizzard will yield sellers more profit. Which of course blizzard does not want to be left out!