I'm going to ask my roommate to eat more quietly
What did she do to make you want her to eat more quietly?
She is always chewing with her mouth open and making noise. It's gross!
I understand that you are annoyed by your roommate's eating habits, but telling her how to eat is impositional. Leave your roommate alone and work on your own impatience.
No, I'm going to do whatever I want and I'll fuck her up if she does not change her annoying habit.
Well, it'll escalate the issue rather resolving it. You can ask her politely instead of making a big deal out of something as trivial as this.