Great work on Mexico, It looks like you better take out Mexico early or it will turn into a wide fortified cultural powerhouse, I like it.
The UA is great, and the rurales are a nice touch, you want those guys guarding cities not on the field (just like in real life)
I love the overall concept and mechanics you have in mind, as well as the Tianguis idea, tho IMHO the Haciendas fit the concept better than tianguis, maybe its just that I see tianguis every weekend, and they hardly seem like a cultural hub. Haciendas on the other hand, were the economy driver for centuries (since colonial times), played an important role in spreading religion and fit the idea of cultural and economical hubs surrounding the cities better as today many haciendas have been repurposed as museums and hotels. Heck, they were so important that pretty much of all the economy on Yucatan depended on them, and some Northern cities actually were inside Haciendas (Chihuahua). Also, little detail, Tianguis are on main plazas and streets, Haciendas surrounding cities, location wise, also works better as a UI.
Great work nontheless, hopefully its not too late to switch the tianguis to Hacienda (its still just a suggestion) I just think thats the one think that would make this mod absolutely perfect.