I agree with -rakkus- approval morale is generally not implemented well and usually is just an early get headache and late game afterthought. I've argued that it should be cut or redone as a policy decision issue which could allow for ideology to be removed from colonization. Most of the responses I got to that were its a decision point but generally is isn't really. Right now approval is pointless and even in earlier versions were it did apply to production it was more in line with that's a nice bonus, why wouldn't I use a tile or starbase to get it? Most of the time its not a question.
Approval should have deeper effects on politics for sure. But the existing political system of the game is sorely lacking; Star Empire, Star Republic, Star Democracy, and Star Federation are nothing more than different ways of making money with little depth to them. In truth, each planet should have its own legislature with the right to spend a certain percentage of net income received on the planet (15% for Star Empire, 30% for Star Republic, 45% for Star Democracy, 60% for Star Federation). The party or parties in control would then spend this money on various programs desired by the populace; indeed parties should pop up on promises to fulfill certain demands of the populace. A world receiving much of its income from trade would probably have demands like improved trade facilities to raise that income, while an industrially developed world would seek further incentives to industrial production. Poor worlds would most likely want economic development programs while richer worlds would seek cultural festivals and the like. Worlds under constant attack would vote for parties prioritizing planetary defense while secure core worlds would not do so as much.
Politics can be greatly expanded in GalCiv3, hopefully with the next expansions/major patches. Currently the game feels like a remake of GCII with better graphics, a less complex (but more counterintuitive) economic planning system, shipyards, and resources. I want the feeling that I am running an interstellar empire, not playing a game.