Governments Mod Idea

Sorry, but I don't think this is possible.  It is possible to increase maximum allegiance through research, but that applies to all planets in your empire.  Also, Sins has no random events such as rebellions, it is a straight RTS in that regard.  And I don't think its possible for the loss of a planet to cause other planets to lose allegiance.

If you want a game with a system where you have to keep your people happy and can do things to boost their happiness, and the loss of a colony will negatively affect the morale of your citizens, play Sword of the Stars: A Murder of Crows.  It has a wonderful morale mechanic, once you get used to how frakking hard it can be to keep people happy especially once your civilians hit their population limits.

EDIT: You can grab the Sword of the Stars Ultimate Collection on Impulse for $29.99.  Totally worth it, althouh I would grab Argos Naval Yards ($8.99, less than Entrenchment or Diplomacy) as well so you can have access to the latest patches.

There is Allegence and Culture in Sins. The rebellion stuff is basically different versions of the little research at the end of the TEK tree that looks like a little angry fist of doom. Basically to put different requirements and boosts to the units showing up in the rebels faction.

I'm currently looking into the programming on how Allegence works. I've I can find some triggers to have at it then I think that portion of the mod is possible.

Basically Just as your and enemies cultures influence allegence and can cause planets to kick you out of owner ship this mod is going after more affects of well, basically causing anarchy, new strategy, and new worries.

I'll start doing this mod and just figure out what can or cant be done along the way.

Lol thanks for the game suggestion though, I'm not much for buying a new game at the moment. My next planed games are Fallout and Elder Scrolls updates.

I would remmoned that you try to find out what can and can't be done first since Sins have some barriers in places you wouldn't expect and these barriers are quite solid.

Insurgency is very different from rebellions popping up on low-allegiance worlds.

Ok, but can't the two be used together to create a similar effect?

Insurgency is a research that triggers sponanteous attacks on enemy worlds by ships that are hostile to all.  To the best of my knowledge there is no way to tie random ship spawnings to allegiance levels.  You might be able to code a research that spawns random attacks on your worlds, but why would you want to do that?

At first I though this was a mod that would try to do something similiar to rise of nations style governments, but I guess that is not the case. Anyways, the main problem with what you're wanting to do is that Sins does not easily allow targetting specific planets under specific conditions. Most of the effects in the game are universal research or abiltities by one entity targetting another. There is next to no support for effects that need to operate completely independent of player actions. The only thing I can think of that might work is heavily modding the pirates, though if it is impossible to give them a tech tree that still might be futile.

To make governments like rise of nations, you'd probably have to use a starbase with only 1 upgrade. The starbase could be the government house. Each upgrade for the starbase would have some kind of universal bonus. 

The only issue would be limiting 1 of these starbases per player.