I had many issues with overpopulating planets being unhappy, overseeing the overall economic impact of ignoring banks and maintenance costs, so I read a few guides and this is the conclusion I got:
o) Your goal in the game is to achieve positive income while maintaining full production!
o) When picking race abilities, go for high Economy and Morale bonuses. That seems to be the best combo to help you achieve your goal.
o) You reach that goal by by paying A LOT of attention to where you build research centers, factories, and when you decide to start building fleets
o) Never overpopulate a planet! This was the mistake I did in my first games and that screwed up my whole idea. Never allow for ore than say 13-16 mt of food on a planet, or otherwise you will have huge issues keeping that planet happy and possibly wasting too many slots on multimedia centers and such which cost a lot of maintenance!
o) I think of planets as following:
- Planet quality better than say 11 with production tiles and asteroid belts -- Production planet. This planet should have a starport, mainlny factories, manufacturing capitol and have ability to build galactic wonders on soil enhanced and such tiles. The planet should have 1 to 2 banks and 2+ multimedia (depending on pop) centers to address economy and happiness. I do not want to lose the potential of offseting the big cost this planet will be to me so I focus slightly on making taxes off of this planet, so I always boost income with a few banks.
- Planet with research tiles- Always a reasearch building on it. Research buildings are expensive and it better cost me less per one to maintain the planet.
- Planet good research tiles- Technological capital. This is the only solution that works good for me in terms of research.
- Good quality planet- Most likely a balanced planet with a starport and 3+ factories and good mix of moneymaking. Research a secondary.
- Poor/Medium quality planet (maybe 8 and below) - This is my moneymaker. Has enough production to build out the tiles (and decomission it if needed), farms to support 9-12b of population, miltimedia centers and banks!
o) Unless your planet seems to be not easily defendable, Do not waste a slot on a starport unelss it's a "production planet" or a "Good quality planet" (see above)
o) Military costs weekly maintentnace. Try not to spend too much in military until you are ready to do smething with it. Produce cheap, slow constructors with small hulls to build economic centers around your strategic populations, capture galactic resources, and even military starbases on enemy teritory that will piss them off (this is for storyline missions) and make them waste their defenders until you are ready to move in.
o) General order of research (for me)
- Overall race stats. Plkanetary improvements and such.
- Econmy level priority.
- Factory level priority.
- Other moneymaking techs.
- Happiness techs.
- Research techs.
- Now trade with your good miliaristic friends when they are a few levels of research ahead of you in some weapon techs, propulsion, or minitaturisation and continue from there.
- Fill in with military techs and plan on getting high damage small ships, then miniaturization and logistics, then high damage medium ships, then even more miliatary until you are much better than the rest.
- Research planetary invasion now.
- Diplomacy and such should be a matter of "taste".
- Wonders and high improvements once you have taken over some good planets

o) General order of shipbuilding
- At the beginning, focus slider on military at least 60%, you should crank out a lot of colony ships (even convert your intial ships to colony) and capture as many planets as you can. Follow the "colony rush" examples.
- Then you crank out survey ships to get you some money back. You have hopefully researched sensor s and other yada-yada to make a decent survey ships. Follow other guides for this.
- Make cheap constructors.
- Make a defender or two.
- When researched enough into good weapon tech, make a small fleet and hit on the first conventient target.
- Upgrade your weapon tech to match the enemy and crank out unbeatable ships. You better be able to do this by now, or otherwise you didn't follow the instructions.
- Build transports on all your starports and wipe out the maps, and repeat the proevious steps if needed.
o) Approval:
- I like to have 100% approval on most planets most of the time to boost planet population. Mid to late game that approval is good around 60-70 percent.
- Regularly examine each planet (in domestic stats window) and address the least happy panet by building an entertainment tile on it.
DISCLAIMER:
These advices are based on my very bad previous experience, limited experience with the DL campaign, forum guides, and a few ow my excellent rounds against the normal AI.
I still have issues with spies though. If 4 AIs are placing spies on my buildings, there's almost no way for me to defend. I have to prioritize to always have one spy spare for "checking on planets", and rest for neutralizing critical inflitrated structures. Maybe someone can advise? Is this maybe addressed in a beta release? Should I install a beta?