Are the students causing the ruckus also older/returning students?

There are some students for sure, but the majority of those arrested aren't affiliated with the uni. I don't know what the age breakdown is for those students who were arrested.

That may also play a role in why so many individuals (reports are around 75) took up the President's offer of amnesty if they would just leave the library, while others stayed.

I'm guessing the people in Gaza, living in a prison camp, being starved to death, being denied water, electricity, and sanitation, and the survivors of those being deliberately murdered, and the survivors of those being massacred and buried in mass graves, feel the same way.

You should have to be a humanitarian or an activist to care about genocide. Being human should suffice.