I think you need to break it down into separate games, in each of which all of the players would have the same role--a game for kings, a game for capitalists, a game for generals, etc. If everyone has different role then they're not really playing against each other. For each game, you can build in the complexity you want (well maybe not quite as much as you want) through the use of cards, like in Monopoly. You can do a lot more with the cards--for example, have the card involve one consequence if the player who chooses it has done X (invested a particular way, chosen war or peace, etc) and a different consequence if he has chosen y. The cards can be designed and weighted in a way to teach the lessons you want, and the players of course would know this in advance. Then you could have a set of different games: the Empire game, the Field Marshall game, etc., even the serf game. It would be interesting to see which is the most popular.
Take into account that I'm not familiar with Civilization.
> If everyone has different role then they're not really playing against each other. There are multiple competitions. There are Kings against Kings. Kings have a "staff" that consist of General, Diplomat and Banker. Capitalists are lone wolves who have loyalty except to themselves. Yet, they can throw their lot in with one King in order to enrich themselves further. Yet, the dynamics of the game see an eventual conflict between the King and the Capitalists because IF a King becomes Emperor, then the King can raise the rents or if a King becomes very powerful then he can also raise rents. Thus, Capitalists have a reason to not allow anyone to become a monopolist.
Yes, it would require a lot of players--something like a comic-con sized crowd. Perhaps if NRx gets big enough, and draws enough young people, it will function as you intend. It could on for weeks, or maybe even all the time, with people leaving and delegating their place in the game to others. People would blog about it, etc. To get it to that level of popularity, it would help to have a version that 4-5 people could sit down and play for a couple of hours, that you could buy at Walmart, etc. If that interests you.