A lot of you haven't seen many Superman comics, have you?
He's ALWAYS getting his suit torn to shreds.
His ass is ALWAYS fucked up, bleeding, and exhausted.
When he stops a train, he uses his feet as brakes, digging into the ground and slowing the train down to a stop - there's no sudden stop. Regardless of what that would do the the trian, the passengers inside would be killed if that were the case.
When Superman saves a falling plane, he struggles. Hell, I recall an episode of the cartoon that had enough realism to have the wing snap off on his first attempt to save a plane.
FYI - Superman doesn't need to eat. He does need to breath though. (I know, shit shows him in space or underwater without a helmet, more on that later)
The whole thing about his suit being super strong was that it was supposed to be as strong as him. I've heard people explain it away by saying his suit was from Krypton. But if I recall correctly (and I usually do) his suit was made by his mother. And the whole thing about the suit remaining intact (although it does get torn to shreds a lot) was supposed to be to all of thta love/family/parents crap.
Superman's powers are:
Flight - Maybe he farts. Maybe his skin emits gasses. This is the worst violation, though.
Speed - He's just fast, ok? His speed varies from Mach x to ZOMG light speed. I put him at really really fast, but no where near light speed.
Strength - He's strong. Ok? There are things stronger than him that kick his ass. Sometimes he'll lift a crane (constrcution crane) by the very top. Or swing a helicopter around by the tail. Other times it's more realistc and he can't simply lift or carry huge shit, but guide it as it falls, or shield people below when it falls on them.
Hearing - He has super sensitive hearing. Cool. As for being overwhelmed by everything - no. Just like your normal human eyes that aren't overwhelmed by light, he can adjust his sensitivity. Just how good his hearing is, however, is another question.
Icy Breath - Simple. He takes a deeeeeeeep breath. Keeps that shit under pressure inside him by simply holding his breath. The temperature of the air he breathed in is now HOT (high pressure). His body temperature quickly balances it out. Then when he exhales, the temperature of the exhaled air drops dramatically, due to the sudden decrease in pressure.
Heat Vision - Fuck if I know. He has lasers in his eyes. He suses the sun's radiation to emit light at a toasty infra red frequency. (The red lines we see sometimes are simply for our information)
X-Ray Vision - He can detect and emit (see above) x-rays. How can he see things normally? Sometimes he is shown as being able to do that, sometimes he is not. Anyway, by varying the intensity of the x-rays emitted, you can adjust how far you see (as a function of penetrating shit) He can certainly adjust between seeing through 1 wall or 2 walls. But he's so super he can make minute adjustments as to whether or not he wants to see through clothes/skin etc. As for seeing shit in color. He's just cool, ok?
Super Vision in general - He can also see really tiny things or things really far away. He's just got good eyes, k?
Superman's powers vary a lot. Deal with it.