6) governments make a huge difference once you get some planets

7) as a general rule, the higher the efficiency of production/research per tile, the lower the efficiency of production/research per upkeep

8) if you're not busy at something else (like colony rushing) kill the pesky minor starbases when you get your own constructors near the ressource

then make peace with them in the same turn or ... kill them

9)  watch your pop, 100% morale allows your pop to grow twice as much

10) depending on your strategy to the game, balancing economic buildings might be necessary

11) research economic buildings and techs with bonuses to morale/econ

last (but not least) galciv.wikia.com is a nice source of info /strategies, even if not always up to date

Definitely dedicate some of your planets for purely making money.  Enough farms for at least 15 billion population, 1 or 2 morale structures, and the rest economic buildings.

Sentient species taste better...

Yes, I think specializing is the optimal way to go with planets.  I specialize every one of mine for either econ, reseearch, or industry.  If you devote a decent % of your planets to income-generating, you wont worry about where your BCs are being spent, you will worry about spending enough to stay under 20k each turn.

I like to get to 20 billion population on most planets (excepting the very low PQ ones) by the end of the game for a higher social score.  So at the end of the game, each moderate to high PQ planet has 2 farms, 1 or 2 virtual reality, 1 fertility clinic (until the pop maxes), and the rest of the tiles for only factories, labs, or stock markets, depending on the planet.  Only my industry planets get starports.

Sentient species taste better...