That's not exactly true though. Sent coins could be returned and relaunch MasterCoin later.
I don't think this is a good idea. This would greatly disrupt things, and a lot of people won't play this game a second time around.
I'm not sure if you were initially referring to my point 1, but he could also relinquish control over the exodus address to someone overseeing the development and integrity of MasterCoin. This wouldn't necessarily change anything you mention. I would assume if that was the case developers should be hired and I'm not entirely sure he wants to put his entire bitcoin wealth at the same risk as everyone else who already sent.
That is completely possible. He can send all funds from the Exodus to a 3rd party even after September 1st.