:Firstly, wtf? Nobody knows what the Big Bang looks like because frankly, nobody's seen it. I'd imagine it would be much more bright though. 

 :Secondly, I doubt that anyone would dispute that Manhattan is a god. However, he doesn't need to time-travel; he exists at all times simultaneously (i.e. in the chapter which is one big flashback, and later when he talks to Laurie "90 seconds ago" and Rorschach in the same conversation (to him, anyway). When asked where he might go next, he suggests that he might leave the Milky Way, but not time-travel. (I do, however, think that he may have "intervened" between Dan and Laurie, as he smiles at them after they've had sex, in the last chapter on his way to talk to Veidt. Maybe that's what he meant by creating life?)