Conflict and settlement pop limits

One of the traits that effects unrest is conflict (I think thats what its called if not I apologize). Now I have no idea how this trait is calculated nor how to rid myself of it. At first I thought you received it from a recently conquered province as it is becoming more settled. Then I thought it was applied when an enemy army went through your lands. But in my Getai campaign Im having cities in conflict despite the absense of these factors. I conquered a barbarian town to the right of the bastarnae province because it was poorly garrisoned. This was done back in 264. In 249 I still have 8 confict in the province, despite no rebels or armies in the territory and a large garrison. whats the story?

quicker question - anyway to raise the pop levels of cities to slow down the game? maybe double each required pop to go to the next level? I dont think so but Im just making sure...