So my question is, what would be appropriate in all of this, for both sides (government/law and student protestors)?
This former Philadelphia police captain says (the NYPD behaviour) is illegal, and it's safe to say he'd be similarly frustrated by the UC Davis officers. [see link at bottom]
The appropriate action is to let a citizen invoke their first amendment rights since no chancellor of a public institution has the authority to ask the police to kick them off unless they're protesting in a genuinely threatening manner.
The 9th circuit ruling I posted in the other thread is a federal law showing that this specific instance is illegal police behaviour. Speaking to the chancellor's call to police to boot them: note that there's no claim of protestors violating laws here when the chancellor tells the police to kick them off public property, she's simply pulling rank and pretending she has more power than the constitution. She does not have the right to do that.