Each pop should have their own ideological views (3 each), when your nation first starts all of the pops should have the same views and those views should go with the government. However as you meet other nations and races with other ideologies your pops may start being influence and if enough pops have another type of ideology a faction forms around that ideology, this means that late game you could have 10 or more different factions. Each factions would have their own wants that the government would have to achieve or the pops in that faction become upset and cause unrest. This could lead to choices, a pacifist faction would want you to stay at war while a militarist faction would want you to subjugate another nation/race, forcing you to pick and upset one. If a faction has enough power you could willingly reform the government around it or, if the government has opposing core views to a faction, the faction could cause a revolution to try and forcefully reform the government.
But other ideolagies will still POP up in your nation due to your nation condintion.Like maybe if the situation is really horrible,radicals will pop up for example.And your people don’t need to contact other nation with that ideolagy in their nation to make it a thing in your nation,can’t your people invent it?
pun is not intended
Yes they will, I never said they wouldn’t but the point of this was for me to present the factions system and possible ways for which factions will form. Civil strife will also cause other ideologies to pop up. Now that’s I’m talking about this I might talk about Governing Values Attraction. GVA is how much the pops are for or against the current governments values. Things that would affect this would be civil strife and other governments. The lower the GVA the more pops will switch to an ideology opposite of the current government.
A special trait could affect GVA, maybe they could be called conformist and renegade.
One thought I had about POP culture is maybe: when you recruit a pop into the army they keep their cultural traits. As they campaign they interact with the other pops in the army and with the culture of the land that they are in, if you take them on a long campaign far away they will start to take on traits of those people. Also their traits can spread to the lands they are in.
Then when they are sent home they will take those new cultural traits with them, influencing the cities they return to.
I don’t think this is any more difficult than building a basic cultural system but would have some really interesting mechanics.