@Lord Santa Good questions. I shall answer.
1.) No. By god, do you know how much work the Administration would need to do to keep all of these bastards in a uniform!? The answer is too much for them to bother.
2.) Injured students, usually go to their Cliques for that. However, sometimes you can't do that. (Poooor, poor Factionless) There is a Neutral Safe Territory, (ie. The Nurse's Office) where they can get patched up.
3.) Class-rooms, well they look like standard stuff, if taking for account for the strange creatures that exist in it. Also depends on the class-room, one for science has really neat large and shiny desks, while like the Art rooms are full of blank and filled canvases. Of course, since it is Winter Break the Administration isn't as concerned with keeping them all, preferring to just keep the 'necessary areas'. So plenty of these classrooms are already covered in taggings from the various Cliques who decided to take the territory. Janitors always complain about having to clean that up before Semester starts up, and others in the Administration bitch about having to fight off the Cliques to reclaim those rooms.
There we go, quick answers for ya.