This basically opens the venue to cheated items and duplicated items, and that goes right against what they are trying to do with the AH. They need to keep cheating and duping under control this time because of that. For that reason alone it's already infeasible.
How exactly having an offline mode with offline character (of course with HUGE disclaimer explaining that offline characters won't work online for the retards who would otherwise be unable to understand it or would change their mind after 1 hour of offline play) would "open the venue" for cheated items ?
That makes no sense, does having an offline mode in Starcraft 2 really completely destroyed the multiplayer part of the game making it unplayable because of cheats ?