I think the problem with rebellions is that they are currently a doomsday device. Either you win before rebellions, or you become unable to do so thanks to them.
The large issue however is that historically rebellions always served a purpose - and yes, they did happen in case of starvation although it was not the most prominent cause. An influential noble/clique might want to overthrow the government, religious unrest, the nobility supporting the wrong side during a civil war, foreign invaders being unable to assert proper control of their conquests, etc... However I realize that right now the game simply is not in a state to simulate those things, so perhaps the rebellions simply need time for their mechanics to come, as it were.
Regarding freezes: I noticed the game did not consume a lot of memory. I still reported the issue because a welcome message popping up in turn 42 does seem like a bug, although just to clarify it was my hard disk the one thing being heavily in use (I was performing a +100 GB installation), ram-wise everything was fine.