Entitled guy demands his roommate stop cooking pork in her crockpot every 2-3 weeks because it makes the apartment smell like pork: 'Open the window or get your own place.'

If he can't handle smelling something unpleasant once every two to three weeks, he's not going to make it.

If your roommates don't do something that annoys you a little bit, you're probably living with a robot and not a real person. If you decide to cohabitate with other people, you have to get used to the fact that they're going to do little things that you don't like, and you're going to do little things that they don't like. It would be borderline impossible to find a living situation where everyone is never annoyed with each other, and if you keep trying, you're never going to stay in one place for very long.

The most important thing is figuring out which annoyances you can accept and which you need to discuss with your roommate. If the bathroom floor is soaking wet every time they take a shower and they don't bother to clean it up, it's worth having a conversation about. But if they forget to take the trash out once after consistently doing so before, it's probably best for the household if you let it go. 

The kitchen is one of the biggest sources of conflict for roommates. If you've devolved to the point where you're arguing about one roommate using a dollop of another roommate's ketchup, it might be best that you stop living with each other as soon as possible. Some people have strict boundaries about what another roommate can do in the kitchen, but it shouldn't be too hard if you're using common sense. If you want to use your roommate's food, ask first. If you make a big mess in the kitchen while cooking, clean it up. It shouldn't be too hard to live with another person, but that wholly depends on the kind of person you're living with.