I'm going to leave an 18 cent tip and get the waitress fired
Why would you leave such a small tip and hope to get a waitress fired?
I want the waitress to feel insulted.
If you think that you had reasonable service then you should tip accordingly. It's rude to tip really low just because you are in a bad mood.
Who cares? Employees need to know that they are worthless and meaningless.
If you feel that way then you should not go out. Service employees deserve respect.