Sounds like you are imposing high taxes. You can control a high population planet but you must mine morale resources, keep up with entertainment tech, build approval trade goods and build on the approval bonus squares when possible.

There is also a limit to the taxes they will stand. The pop 3 planets are easy to keep at 100% approval but your economy must have people to grow.

All this could change a lot or a little when the public version comes out

A few things and remember I am playing at no higher than normal difficulty:

I don't recall GC1 having a default tax level that would keep the approval at 100%. I want to say it was related to PQ, distance from home world and improvements with about 39% being the optimal tax level (hard to control over that).

In GC2 the average seems to be more important than the individual planets, particularly when the planet is in your sphere of influence. I have had core planets stay in the high 30s and low 40s for many turns while my average approval is over 70. Remember, in the real world political approval is seldom higher than 70%.

If your planets are mixed in with a high powered rival it can get dicey but it is managable. I played a game with the I-League becoming dominant and the had planets throughout my system. I had a couple of colonies flip to them (if you ever lose them you will never get them back peacefully) but I was able to stop it with culture starbases.

As a culture and diplomacy player, I really like the way that moral works in GC2 (so far). Coping with it adds to the game srategy. I can also understand that players who want a full time shoot-out might be distracted by the moral nuisance.

It will probably be easy enough to mod the moral to a point that it will not be a factor but that might effect your ability to post scores.

Have you went to the detailed portion of the planet screen and added money to help with morale? I have figured out that 2% per PQ level of the planet helps a metric KAT ton with keeping the civs happy and otherwise ignorant of the sneaky low down double dealing swindlers that are running the beauracracy.... er uhm... oppsseee yes we just aim to please our folks is what I meant to say!

W/R
Suralle Straykat