If only you could sneak in a step ladder like my cousin was able to sneak an entire pizza into a movie theater once.
The problem isn't sneaking one in, the problem is I need to go buy one.

Most apartment regulations are pretty lax. You can hang posters, so long as you use sticky-tack or something else that won't remove the paint (no tape). Most places will allow pets under a certain weight, and caged pets aren't regulated at all, so go ahead and breed scorpions!

As for repairs, if you know what you're doing and the repairs are minor, you can get away with doing them yourself.