On the subject of the God plot: I don't think it was their intention to make Chuck God when they first introduced the character in S4, but from the start of S5 it was clear there was an active God in the story from the moment he yanked Sam and Dean away from Lucifer and into the plane (which I always thought was a really weird start to the season btw) and then there was Castiel's resurrection, Dark Side of the Moon, and Castiel's resurrection. Again. Since they'd actively made God a character I suppose there was an impetus to identify him, and Chuck was the obvious candidate. Having said that, I think Kripke deliberately left his status ambiguous so that the character could have multiple meanings. It was implied, but never confirmed. I feel they've limited the character by positively identifying him in this way. Having said that, I think Robbie made interesting use of the trope.