Hello Kleitos,

I found in your game just the mentioned rebellions, fixed them and was able to play another 5 rounds without problems, the file one turn after yours can be fount here: http://ul.to/3yjepe

Concerning your second post:
There is no negative population, so the cheat simply will not work anymore beneath 400 population. The pitchfork-symbols will not disappear right now, the will get actualized in the turn who ever owns that settlement.
You can provoke rebellions, for some factions is this a very good starting tactic, but there is a chance the game will crash, it must not crash but don't be angry if it does.

XSamatan