Bureaucracy: lose 3 tech levels when using the black market do to their trading leverage.
Capitalists: Reinforced factories and refineries (last to be destroyed in combat)
Communists: Due to the fact that communists markets are inefficient, one less trade is possible. (or -2 production modifier) Since communists govs control the media, revolts are impossible.
Fascists: Their military dominance allows them to steal their newly conquered b-miner's vassal, reducing the stolen vassal's vassalage by 2 (countered by a church)
Monarchies: For each vassal they own, they reduce their tech level penalty to ramul by 2.
Technocrats: Do to their reverence of technology, they have perfected their shield and it now protect the beacon of knowledge, THE ACADEMY! However this new addition seems to pollute their land. (+2 pollution?)
Theocrats: Cost 1 food to change between theocratic ideologies. (since they can attack differing ideologies?) Must have a church to gain luck bonuses. (god only rewards the faithful)
I welcome comments to these suggestion to tweak them!
1 food to change between theocrats is a little harsh, isn't it? Especially as there are such small differences between the faiths and those that are present are mainly aesthetic. If you did feel there was necessity for a cost, it should be something small, like a coal. But I think even that is too much.
I like the suggestion for fascists. You didn't say what happens if your conquered opponent has more than one vassal, but I'd suggest you stole one, at random, rather than the whole lot.
As far as I know, all theocracies can attack all others... It doesn't say anything about it having to be a *particular* kind of theocracy. So there isn't any need to cost the change at all, unless you're wanting to add that... but why would you do that? I don't find theocracies particularly overpowered. Sure, they're lucky - but if you make it require a Church, you make starting players suckier and don't reward later players (as they'll already have churches for the accuracy bonus as well)...