Do you think I should start enforcing my daughter's roommate contract?
She sounds like a big hassle. How would enforcing the roommate contract help?
She doesn't clean up after herself, she eats with her mouth open, she has dirty clothes all over the floor, she uses my personal stuff without asking, makes noise with her headphones, comes in late and wakes me up, don't bathe regularly. I hate her.
If your daughter's roommate is this difficult to live with then you should without a doubt let her know that you would like her to switch how she is acting. If enforcing the contract helps you do this then so be it.
She doesn't want to act differently. Plus, the contract is all about rules and fines for breaking them.
You have been so patient and that is respectable, but from what you are telling me, I think you are in the right to enforce this contract and put your foot down. Nonetheless, you are teaching her life lessons. I support your decision.