Something thats been really biting at me, other then my save game after taking over all of europe, africa and half of asia became corrupted is that the amount of certain religions don't change after taking over a country, playing as Germany, and they had mostly christian and other religious percentages, but even when i took command of the middle east, asia, including india the percentage of predominatly asian religions didn't change.
Didn't think that was right, as each religious group should increase or decreas upon the land i owned, which would affect my research decisions based on how eithical each religion thought it was.
I don't have the save game anymore, after it became correputed i went into a blind rage!
I'm pretty sure that feature doesn't do anything at the moment. I'm also pretty sure it's not even all that accurate, there isn't a single percentage point of aetheists on the map. Yet I'm pretty sure China has a fair number due to its form of communism. Either way religion doesn't do anything in the game, so it really doesn't even make much sense to have it in at all.