im in the exact same freaking situation aside from the anger issues.
i also work at a pizza shop, my manager is still a teenager, and has no immediate "higher ups" in store
he thinks that because he is on salary now, that he can come and go as he pleases, (which ends up being ~20-30 hrs a week)
and tells us (the "team") if we dont stay late, he will fire us.
he takes money out of the till to go gambling, makes poor decisions, and makes schedules up to 3 days late.
i didnt work this monday, tuesday, or wednesday because he didnt make the schedule.
i've also had to act as assistant manager the past 2 days (i've been employed there 3 weeks -.-)
i also will be staying, purely for the fact that i have a damn good chance of being promoted to assistant manager, and that shit looks great on future resumes.
if your able to do the same as that, i'd say stay, or tell your district manager about the issues your manager is having, and let them deal with it.