Re: Superman's power level
This should be early post crisis all the way. A nuke will kill him. He cannot move planets or even land masses. For the love of God, he cannot breath or talk in space. And he damn sure can't go lightspeed.
Even with those limitations he's still extremely powerful. His top flying speed should be something around Mach 10(which would still allow him to get anywhere on Earth within a couple of hours); he can still bench press a couple of skyscrapers like the empire state building; and nothing short of a field artillery canon to the groin is able to cause him pain(though still not able to really cause any more harm to him than an ordinary person getting shot by a pistol whilst wearing a bulletproof vest). High voltages of current can pain him but not do much more than that(and I'm talking at least a million volts to even begin to cause him pain).
I think all that would suit a movie Superman well. And I'd keep all his extra powers(X-ray/heat vision, freeze breath, etc.) intact too.
You know, it occurs to me that Captain America is basically the superhero equivalent of Mary Poppins. Practically perfect in every way and all that stuff.