Cmdr1989,
1. Pop growth is doubled if your planet morale is at 100.
2. There is a very good article by Brad in the Encyclopedia about Influence and how it works. It explains the relationship between cultural influence and loyalty/rebellion.
3. Destabilization lowers target Empire morale, which can lead to planets rebelling and voting to join the highest culture-ranked Empire in their sector.
4. Income is a function of population and tax rate. There is a "sweet spot" for maximizing your income vis-a-vis your morale; simply play with your tax level(s) to find it. (By setting taxes to 100 and then notching them down 1% at a time, you will see this in action. It is a good learning exercise to try one turn.)
5. Buildings with Econ bonuses (Banking Centers, etc.) will promote your planetary tax base, and thus revenues.
6. It is very hard to obtain (and keep) a positive cash flow at the start of the game. Generally, you have to set taxes and spending so low, you only get 1-3gc/turn and are producing nothing. Instead, view your initial treasury of 1000gc's as a down payment to buy your first Empire. Colonize 5-6 systems, research the basic buildings (Mfg Centers, Fusion Power Plants, Banking Centers, Research Labs) and starships (BC's, BattleAxe's, BattleHammers), and use it to get a production base built which can carry you forward into the mid-game.
~SDC~