Superman could just let his astounding powers go to his head and become a self-righteous super-vigilante or demi-god, but he doesn't. We see this trait in others (Lex Luthor among them). Lois is fearless and smart, but she still needs rescuing almost continuously; ditto the less resourceful Jimmy Olsen.
Intense animated violence, to the point that Superman bleeds. Characters are killed, including (off-screen) a child. There are beatings, and (off-screen) heads are broken, spines are snapped -- animals as well as people. One character shot to death.
Nothing overt, but it's clear that Superman and Lois are lovers and cohabitate when they can. Naked male superbodies in cloning chambers have private parts obscured (rather amusingly, a la Austin Powers) by gravity-defying mounds of liquid.
"Hell," "ass," "rectum," and the euphemism "frigging."
Tie-in to vast quantities of related merchandise.
Drinking under duress by Perry White.