Very low chance of this happening, but if I have been offered a spot off a waitlist and then decide to commit (pay the deposit), but then am accepted off another waitlist to a college that I would rather go to, am I allowed to accept a spot in the college I would rather go to and then call the other college telling them I have been accepted off another waitlist?
Yes, of course you’d probably lose your deposit. As long as you are committing/depositing consecutively and not to more than one at the same time, that’s fine.
^ Yes, you may accept a second waitlist offer, provided you notify the first promptly that you will not attend. In all likelihood you will lose your deposit at the first one. Consider it an insurance policy paid to guarantee you would have a college to go to.