6.
OBSERVATION: Citizens and improvements (and asteroids) barely matter relative to colony worlds.
I won't comment on balancing, but I also find it hard to care much about citizens on my planet(s) either. Perhaps some sort of small leveling up mechanic for citizens (their bonuses just increase over time if they're not reassigned or whatever) would change this.
7. OBSERVATION: Credits scale poorly throughout the game. Early game you're cash poor. By midgame you have more money than you know what to do with and are making it rain like a rapper at a strip club. Perhaps ships should have maintenance costs based on their hull size to balance things?
Unless it only comes in LATE game, ship/fleet maint doesn't appear to be in yet. So the days of fielding a vast armada for free are probably numbered...
Apart from this, money works the way it should IMHO. Just like being rich in real life (not that I would personally know), money is an abstraction. If you don't have any, it sucks. But if you have some, you quickly realize that it doesn't actually do much for you. It doesn't make you happy, it doesn't do anything about loneliness, nor personal inadequacies, etc.
In terms of the game (and macroeconomics): money is fundamentally a claim on the underlying capacity of the economy for which it can make claims. Thus it can only buy what is actually producible, and faces severe diminishing returns. For example, Bill Gates cannot buy an unpolluted, happy and worthwhile world to live in, despite having more money than he can spend. The Iridium (ie 'Corporate Sector') cannot win a war with their bank accounts - at the end of the day, they actually have to be able to make ships with appropriately researched techs - if they don't have these underlying social structures they cannot and should not be able to win a war. I actually think money is actually implemented pretty well in GC4. And look forward to when severe economic repercussions result from waging war in game. Diverting ouput (ie raising taxes) to fight a bunch of dillholes far away should always be a choice you need to doublethink (unless you're Drengin or Krath Clan - in which case just attacking everyone is just groovy (which is why you play these guys)). Fielding fleets of warbirds will be more interesting when ship maintenance costs are in game ...
cheers,
-tid242