Maybe Superman's flaw is that he's too powerful?
http://www.youtube.com/watch?v=Cl_5UwS57X8
Sort of a Great power, great risk of hurting people.
He's a guy who if he punched a normal guy with even a hundreth of his full power would turn them into hamburger. His fights with people who can actually go throw down with him cause massive collateral damage, endangering anyone nearby. If he used his full speed in a city, the sonic boom would blow out every window nearby.
there was a scene from Superman returns that could have been done that way: When he's stopping that bank robbery, and a guy turns a machine gun on him. Sure, it was never going to scratch superman, but the bullets could easily ricochet off him and hurt someone else.
Spend the movie showing how he has to touch the world with kid glove on the whole time. Maybe a scene where he has to sit and evaluate a situation with his powers, and analyze it like Robert Downey in the last Sherlock holmes movie.
" Three men in the office with machine guns. Two hostages. Come in through the wall? No, its load bearing, i could bring the whole building down. Front door? They'd shoot, high chance of ricochet hitting the hostages or them. Not possible to melt them all with my heat vision in time. Superhearing reveals their heartbeats are raised. They're scared, they know i'm out here. Leave the scene, let things cool down, and let the police negotiators handle this? Unlikely to succeed without aid. ::Looks into one of their wallets with X-ray vision and sees a drivers license:: Name XX, lives at XX. Picture of older woman, likely mother. Find mother, have her call into the room, hope this can defuse the situation."
The end of the movie he finally gets to cut loose and fight a villain who he doesn't have to hold back on.
Showing him as a person who has to think very carefully before he does anything, and not just some dumb brute who goes SUPERMAN SMASH! all the time. It would be an interesting characterization, at least I think.
So many recommendations for All star superman. I've never read it, but now i'm thinking of picking it up.