One of the finer points of SMAC was the great little government system they had going; different techs opened up different modes of governing in each of several different areas (justice, economy, infrastructure, environmental policy, etc). You could then choose amongst those policies that you had researched, each of which gave you certain faction wide bonuses and negatives (eg: "police state" reduced your unrest, but at a cost of your gold production, while "green economies" increased food production and happiness, while reducing hammer production). In SMAC, you could change these on the fly in response to differing conditions, usually with a couple of turns of unrest if you went from a facsist police state to a democratic green economy all on the fly. There were also limits to how often you could do this (I seem to recall it being a fixed 2 turn wait, but a better option might be to have one additional turn of unrest each time you have a policy change).
Something like this, IMHO, would be a good addition to FE after the first release to help in defining both how your society works and what it values, as well as the diplomacy with other civs. Societies with large differences in how they govern will likely be less friendly than those who share many common values. Certain leaders could also have preferred values, which could double bonuses and penalties if that leader was using that value.
Think of values based on magic (think of "mystic society" or "enemies of the titans"), economy ("the dwarves were children compared to how deep we delve" or "all rocks are sacred"), justice, freedom, hero worship (things that strengthen or weaken heroes, with suitable tradeoffs on your populace), etc.