They almost always hold Doctoral degrees, or the most advanced degree in their field. Buy a box of manila file folders. Don't let anyone criticize your taste. A bad dye-job will grow out. A bad tattoo won't.
People can die from infections.
If you don't smoke, demand a nonsmoking roommate. When making personal decisions, do whatever the hell you want. There will be people with whom you share interests, no matter how weird or unique you think you are. Your college years are your best time to experiment, question your assumptions, and try on different hats. Grow a beard.