Committing Before Receiving Financial Aid Offer

If your expected family contribution on your FAFSA documentation is $0.00 and it's a state college, it's highly doubtful that they would modify it to point of not making your college education UN-affordable. I don't know UC school finaid policies, but it's quite a normal and common practice to have students on full financial aid participate in a work study program to offset some of their expenses. I would sit tight and be patient and wait for your actual letter to arrive prior to making any moves.

Your last question makes no sense to me. A college will not rescind your acceptance unless you have committed some crime or failed to minimally perform academically or have some disciplinary information that wasn't available at the time of reviewing your application. And if they do rescind your acceptance, then you would lose your ability to attend that school.

Once you have informed them that you have accepted their offer to attend the school in the Fall of 2022, then you have an obligation to attend. If you don't receive enough financial aid, then you can discuss the matter with the financial aid office. Either they will up the offer or not. If they don't, then you have a right to back out of the agreement to attend the school because you can't afford to attend the school? Does that make sense. They would release you so you can attend a different college without penalty or being black-listed. But you can't just walk away without a legitimate reason at this point.

Good luck.