HUGE Spoilers... Well, worth a read, anyway... Went rounds on Reddit. Figured out almost all of this, and then someone got on and pointed me in the right direction. Great theory. Explains the only thing I couldn't understand. And takes it back just a little bit farther.
I can honestly say that I never want there to be a Sandman movie because, I just think it wouldn't do the source material justice. That said, if it ever did happen, Benedict Cumberbatch is a dead ringer for Morpheus.