It's importnat to remember, as others have suggested, that when you fill out the paperwork, you agree to follow their policies.
As for all the body mods, I look at it this way: no one is forcing you to get them. By getting them, you take on the responsibility to take care of them, to keep the bandages on for X number of days, and to realize that you are limiting yourself, right or wrong. For instance, my friend's boyfriend wants to become a cop, and get about 7 more tattoos, but he know that if he gets them on his lower arms, he will have to wear a long sleeve shirt whenever he is at work, even in the summer. It's not necessarily right, but such is life. If you work for a corporation, it's the same thing, and even if you work for a small business (as I believe Steph suggested) you have to follow the rules.
It reminds me of this debate over at slate regarding relgion at the workplace: http://slate.com/id/2120789
In other news, my mom works at JoAnn's, she hates it, but they get cheaper machine repairs as well as a free crafting class every quarter. I work in the retail business too; I am not suited to it, but I signed up for it, so I simply grit my teeth and focus on the nice customers and cool co-workers.
Good luck! Get a campus job in college; they are better, but you will soon learn a job is a job and they usually will suck in some way.