Does AI stick with NORMAL tax or does it set it differently depending on the order of the populace?
Interesting question. I don't know, but I would suspect if anyone does, they would be in the modding forums...
I don't think they have a tax system. I think they get a figure based on some math equation based off of total provinces, king's purse, difficulty, upkeep, and how many of the provinces are cities or castles.
If you open your faction tab, youll see that there is option 'automanage taxes only' and 'automanage everything'. AFAIK AI uses the automanage (which was discovered as they started mass-producing unique units of the crusades campaign - as if you put automanage on there would be a chance for a human player to get more uniques).
So i bet they use automanage taxes, so that it sets the taxes on highest possible level that the city's public order allows.
The AI does indeed use automanage (for everything.) You can see this yourself if you are hotseat enabled; just use the control {pick-a-faction} command and when that faction comes up you will see that everything for it is set to automanage. The AI even uses the different flavors of automanagement, taxes are set to whatever level the population will stand.
Yep, they use taxes alright. When you are trying to make a city rebel they will lower taxes to raise public order to an acceptable level.