Religion in Society?
If the game included embedded (fictional!) religions, or somehow allowed players to form new religions (say it takes ten players to agree on a religion or something) a new dimension of society would be added that could diversify play, increase versimilitude, and de-emphasize purely military force (seemingly a goal of this game). Resources invested in religion (support of "clergy", buildings, celebrations/holidays, etc) could affect morale of populations including soldiers and everyone else. Maintaining this side of the game would challenge people to think more about their societies, and penalize people who just want to "use" their societies as cannon fodder. Civilization IV added religion, but I bet we could do better in terms of flexibility and creativity.
Different religions in conquered provinces leading to some kind of morale bonuses or penalties depending on whether you cater to the other religion, or forcibly change and ignore their beliefs...
So now... being a Domo myself... I get to be awesome and walk around being more Domo-ish... 
As a Athiest, I dont personally believe in the divine, but I am all for using "the divine" to manipulate others