Re: How will a sense of danger be established for Superman?
I think they're already establishing that by having General Zod and other fellow Kryptonians for villains. There, you already have a conflict that is just as powerful as, or even stronger than Superman himself. That sense of danger is definitely going to be present, since we know and have seen briefly that Superman falls down on his knees and spits out blood.
"Twenty years in Gotham; how many good guys are left?
How many stayed that way?"