optimal population + crash

I normally get populations on planets 8 and up to 10 billion. Which is just a level 1 farm on top of the 8 billion that planets have without any farms. This allows me to only use 2 entertainment buildings to keep very high approval rating. I will often end up with about 80-85% approval while taxing them at a 79% rate. If not better approval due to any mining starbases and crap...but..just my opinion..I feel about 10 billion is good. Sometimes if it's a very high PQ planet, then I'll put more farms with more entertainment buildings as needed.

I don't know about question 2...erm...try the support forums?

For Twilight: My standart for meduim class planets is 20 billions. I use to play at large maps so I need at least 2 morale resourses (with full mining bonuses), and at least 2 economic resourses. I have taxes at 35-28 % in the middle of the game, approval rating 75-85 % and earn about 1000-2000 bc per turn. I play now only by humans. For more income i use to trade with Iconians for their wery useful Merchant Trade Complex (50% economy bonus).

is morale and approval rate important?

what does it give you other than not rebelling?

what are the benefits of high approval rate?

Planetary morale above 75% gives you a 25% population growth bonus.  Planetary morale at 100% gives you a 100% population growth bonus.  This bonus is multiplicative with all other bonuses, not merely additive.

Population won't grow if planetary morale is below 41%.  Population decreases at the rate of 10% a turn if planetary morale is below 21%.

It's difficult to win an election with less than ~55-60% civ-wide approval, with 65% giving you an almost guaranteed win.  This doesn't have the effect that it should, however, as your civ only cares what its approval is for the turn of the election, so you can run higher taxes for all but two weeks out of the year.

See also: Population and Approval

thank you for the comprehensive answer.