With regards to trading, word has it from those who talked to Mosqueira one-on-one at a BlizzCon mixer is that they have zero plans for any sort of trade system (the plan is to get the loot system correct and used alongside enchanting). Josh even answered it as such during the Q&A part of the panel:
Question: With the removal of the auction house, what if any sort of sanctioned trading model will you put in, or not put in to protect people from everything that happens in Sanctuary and not just Evil monsters?
Mosqueira: Right now we are still in the process in figuring out what trading means for Diablo. There is a social component that we still want to retain, but at the end of the day, it’s kind of fundamental to our loot 2.0 philosophy. We feel that finding items in-game by killing monsters should be the most rewarding, most satisfying, and the best way to gets your hands on those items.
