I see one flaw just by looking in South America(where I live). not very accurate for countries like Argentina, Chile and Brazil(I am Brazilian living in Europe atm). You should be seriously careful when comparing us with today's Venezuela or Bolivia, for example. Theirs is a pseudo-democracy that is really just a dictatorship dressed up as socialism to their own people.
Now, if I understand correctly, each of the countries with the same ideologies will also have the same civics? Or is it same favorite civics? Well, anyway, if you take South America, how can you put countries like today's Brazil and Argentina with countries like today's Venezuela and Bolivia? Completely unrealistic and would break the immersion for any South American playing it. Our government systems are very different and you really should be careful with what you do there.
Just the fact that Brazil speaks Portuguese and the rest speaks Spanish should give you a clue that internally we can be very different. Also, the fact that Spanish South American countries got their independence by war(mostly with Bolivar's influence, which I guess the stupid term Bolivarianism came from) while Brazil claimed its independence in an almost bloodless manner should also make you see that. In fact, the Prince of Portugal(Dom Pedro I) claimed our independence himself, he really liked our country it seems. Of course, this is just an example, but I bet things are a lot like that in other parts of the world too. Generalization is bad, so careful.
Or maybe I understood something wrong? Well, just giving input! Just hoping everything will be perfect for this mod!
Things can always be "fixed" in newer versions though.
Edit: Ah, and good luck, that is some insane amount of work!