And yes, he should have armor. There are plenty of times when he's getting beat up and armor would have helped. The way he fights and the kind of powers he has favors armor more then spandex/tights, at least IMO.
Isn't that what the belt is for? Though I can understand the height thing. It does look a little odd sometimes in the comics.
No, he doesn't need armor. Even though writers in the past have strayed (Byrne) the mythos keeps coming back to the costume being woven out of Kryptonian material. Indestrucible, just like Superman. Kryptonian armor may be a little tougher, but under a yellow sun, there would be no difference. And HOW does Clark keep that armor under his clothes?
The belt is too thin to break up all that blue. To me, going back to Carvill since he is a real world example, is a blue blob with a cool S insignia. I love the insignia for the movie. I wish they would have used that for the comics!