Great discussion guys.

Here's what I was thinking of doing:
Each civ would have to have a Government (similar to the way Civ 3/revolution did it); it doesn't make sense having a Government System or Ideology without one. Each of these Governments would emphasize certain things (these can be adjusted by those who know more about how Governments work). Monarchy would be military/wonder based (don't know yet), Theocracy would be faith, Republic would be expansion, Democracy would be happiness/CS (don't know yet), Autocracy would be combat, Communism would be production, Corporate would be gold, Ecotopia would be growth, Technocracy would be science/specialist, and Virtual Democracy would be happiness. There is some overlap (Monarch & Autocracy, (Virtual) Democracy), but this is just an broad view.
The governments would get away from the +x yield to y system, so that they can be useful all game long. Haven't thought of all of the effects yet, but Nuukov (Nuclear Dude) and I brainstormed a while ago and came up with plenty of options. These Governments would essentially define your empire's play style. For the Governments, instead of accumulating culture to further them, they will automatically be enhanced at the turn of a new era (so a new "policy" would be added at Classical, Medieval, Renaissance, etc, etc). This will further keep the Governments more or less equal with each other.
So now the Ideologies and Systems would play in to the Government system. I was at a loss for how to do this, but President's post opened up an avenue that we might want to explore. The idea you presented is very complex, but it might just work. The question here is whether to treat the ideologies as their own policy trees, or if they should be a stand alone bonus. Take Pacifism for example, which improves CS relations. How would it interact with some of the other Governments? Should the effect read something like "If you have a Democratic nation, then...," or should each policy affect some part of the Democracy? And then if you switch to another Government, the bonus would change. The second option is much more extensive, but it would be really hard to find a way to find strike a balance between all of the options. Granted some combinations (Demo-Pacifism) would mesh better than others (Mono-Pacifism).
And finally, how would we distinguish the bonuses between Ideologies and Systems? If they both just boost an aspect of the Government, then they might as well have the same name. Perhaps we could have one that deals with domestic affairs, and another that focuses on foreign interactions?
So yeah, that's what I've been thinking about. But, before we let our imaginations run too wild, we need to make sure this is all possible. Fires, is it with lua?
