1) A strategy I use when it is a race to gobble planets is to only have a few of them actually building anything. It takes a while for the population to grow sufficiently to support the infrastructure, so building a bunch of stuff without the tax base to support it can create a real headache. I'll build a couple planets up at a time, buying whenever I can, then once one finishes I'll start again on a new one.

2) I usually will only have one or two planets a system with a starbase, and only a handful of planets that actually build ships. The other starbases are only there in case I need to buy something. I would rather use the spot for another tech building and focus on better ships, rather then more of them.

3) I try and get this very early due to the bonuses involved, usually once I have trade and xeno ethics mastered I'll go for the government stuff and use tech trading to make up the difference (especially trading the "trade" techs since they work to your benefit, a foreign trade route to you gives you both money and diplomatic stability, and the AI pays out the nose for the upper ones).

4) I almost never build them unless there is a resource right in my back yard, or if I have one planet as a trade hub, in which case I build them early.

5) I don't know actually...

6) I rarely split up factories and tech buildings on a planet. I'll build one or the other, but not both (unless there happens to be insane bonus tiles for both). The reason for this is that, due to my aforementioned emphasis on a smaller but much better fleet, I only have a few planets that build ships. All the other planets serve me better by only having research buildings, and buying any upgrades they need.

As a side note, I also always use my second planet in my home system as my "wonder planet". All wonders are built there, and only there. If I have something built on it taking up a slot when I want a wonder, like a research building, I just bulldoze it and build wonder "x". Yes, it puts all my eggs in one basket, but if the enemy is invading my home system successfully then the game is most likely over by that point.

Since it never hurts to get some other views on the matter, another reply:

1. Be sure to survey as this will reap some 500 and 1000 bc anomalies.
I often choose the political party with economy bonus + spend some ability points on economy. In addition you can sell some non-military, non-diplomatic techs to the AI. Don't grab too many low quality planets (below 6 or 7). Especially low quality planets in a system where you have the high quality ones, will fall into your hands after some time anyway (your influence will grow and the low quality planets will flip to your side). It's also a good idea to research some early economy techs + governments + some like planetary improvements or population growth that in the end all improve your economy.
Once you've had the first colony rush and grabbed resources, you can build a few traders to gain some more bc's as well as improve your relations with the AI you're trading with.
By the way, you should leave production input at 100%, otherwise you'll lag behind the AI's.

2. Depends a lot on the size of the galaxy. For tiny/small I usually only have 2 planets with starbases; for medium it can be 3-4. To defend from troop raids I would recommend to have a few fast ships with good sensors, and try to intercept troop transports before they can invade. The AI will often send them without support, so they're quite easy to take down if you see them in time.
There is no minimum tech you need to have, but the best way to prevent most AI's from attacking is to have a higher military score (check the graphs in the bottom center of the screen) than the AI's. A building available at the end of the diplomacy tech branch (something control center) helps enormously with that, boosting the military score of one planet by a factor 3 or 4.
It also helps to pay some AI to attack another, weakening them both.

3. Everyone has to choose his own strategy, but I often research first some universtal communicator, planetary improvements, economy, then after that interstellar republic (or more general: governments) before starting technology or military techs. At any point in time, just look at the benefits of any available tech, versus the time it takes to research and your needs at that moment.

4. Really early, just after you've built (and bought) enough colony ships, build & buy constructors to race to the nearest resources. Make it a priority since the gains are important (especially after you've added some more expansions to the starbase, you can easily get a +15% bonus to economy, military,research, etc.)
Though this is a big area for improvement for me as well.

5. I think they do (I'm sure some people on the forum will know this, let's hope they pass by). In any case you should use those 10 points! On higher difficulties it's already hard enough like that

6. Really depends on the strategy. Many people go for all factories or even almost all labs. For my home planet I typically buy 1, build 2 more and speeden up by buying 2-3 turns before they are completed. Afterwards if I need more focus in another area I might convert one of the factories.
For PQ 7-9 you can either go for all labs, or do like me and build 2 factories, then fill the rest with labs. As soon as the labs are completed and the population reached a decent size, I often convert the factories to economy centers if my economy needs a boost. If you're going for an influence victory, go for 1 farm, 2 morale buildings on each PQ 7-9 planet.

By the way, in the Metaverse section of the forums, thread "Metaverse league round 6", have a look at pages 13-15. Some expert players shared some best practices there that allow them to achieve 0 year victories. Several great ideas there!

1. Build economy boosting buildings and build them fast. If your are into micro-management, you could also use spare colony ships to transport troops to your freshly colonized planets or you could design a colony ship that holds half a billion of people.
More people in the beginning = faster growth -> earlier in the greens.

2. I like having a starbase on every planet. Otherwise, you would waste the production created by your initial colony, once the colony was developed. Think of the starport as giving one tile away to get to transfer the production into military production. Seems a good deal to me.
Furthermore, when I build up my invasion fleets, my transports have to come from somewhere. I do not want to drive them around to get the troops on-board. Take too much micro-managing and time.
More starports = no loss of production -> transports everywhere
Defending from troop raids ... like someone said before: Build fast ships. And research Sensors V and build the Eyes of the Galaxy. That is the best non-evil wonder out there, if you ask me. I never miss it.

3. StarFed? Rarely get to that ... should try it though.

4. Constructors ... difficult. Having some around is always useful. Yet you have to calculate wether it would be cheaper to build some attack ships and conquer a new planet, rather than building up an economy starbase (do not forget to discount the research costs).

5. Like Wyndstar said: The AI uses its points, so you should, too.

6. It depends. If you want to develop fast and you have the money to sustain it, build three factories, fill the rest with whatever you desire and then build over the factories. Possibly gets you going faster. Haven't calculated it, though.

1: Civilization design is how you fix this. Focus on population growth, economy, and morale. NEVER raise your tax rate to the point where any world other than your capital is less than 100% happy. Your capital is probably going to have to live with relatively low approval, since 16-B people are hard to keep happy on one world.

The key to understanding how this works is as follows. You get money per-planet based on the tax rate and the number of people there. When you build a world in the early game, it's only going to have 250,000 people there, so it can't make much money. A world "turns the corner" when its population + tax rate have risen such that it makes more money than it is taking up. The sooner this happens, the sooner you can afford to expand. That's why population growth is so critical; it makes the population grow faster, which allows it to turn the corner sooner. And with population growth for a planet doubling with a 100% approval, you need to keep early worlds happy.

Also, make sure you don't over-expand. In the early game, your capital is where you'll be making most of your money, so get a couple of base factories and build econ (and a few morale) buildings. It's a PQ10 (or better), so you should be able to build quite a few.

2: Starbases should be built on an as-needed basis. The AI likes building them, but they don't usually build them efficiently, so I wouldn't be concerned that they have more than you.

You should build Resource starbases whenever a resource presents itself. Obviously prefer ones in your territory, so that you can defend them should war break out.

As for other bases, I find battle to be too fluid (in terms of where it happens) to make much use of military starbases. And I don't play the influence takeover game (it's far easier to just invade), so I never use influence starbases. Instead, I go for econ starbases. Particularly, the planetary production ones.

Remember: you can only build 4 non-resource starbases in a single sector. But the effects of them can overlap other sectors. Worlds near the border of two sectors should be specialized as either production or technology worlds; that way, they can get the effects of 8 (or more, if near the border of 4 sectors) econ starbases on them.

Do note that this is mainly a mid-to-late game strategy. It's for producing those really big ships that a "normal" world wouldn't be able to.

If you really want to turtle, focus your civilization on Diplomacy. That will keep the AI's off your back. But a weak military will draw the evil or aggressive ones to you. For that, build a few weak ships with a gun on them. That, at least, will keep you from having no military. Also, keep the aggressive AI's busy by making them fight each other; your high Diplomacy should make convincing them rather easy.

Once that's done, just keep the wars going, but make sure nobody wins. If someone looks like they're winning, try to send more civs after them.

The other thing is that, at the bottom of the Diplomacy tech tree is the Spin Control Center. Build that, put a bunch of those weak ships on the world where you built it, and the AI will think your military is massive. So they'll leave you alone.

3: Since I start off my games with large econ bonuses, I don't bother with these techs until the mid-to-late game. They're more important if you don't already have econ bonuses from other things, like intrinsic civilization abilities or an econ Resource.

4: When you need starbases. Since starbases are built as needed, so are constructors.

6: Any planet, no matter how large or small or whatever purpose you task it to, needs 2 factories. It's generally impossible to get decent production from them with less, and even a planet without a Starport needs something.

I tend to group planets into categories based on the number of available and potentially available tiles. For example, your "Mars" PQ4 planet in your home system will typically provide 3-4 tiles per terraforming tech. Since it is going to be a large planet, but isn't so yet, I tend to build on it as though it would be a large planet. Similarly, PQ7-8 worlds will probably end up only as PQ12-14's, so I build as though they were.

I segregate my worlds rigidly into 3 groups: Tech Worlds, Production Worlds, and Money Planets. Money Planets are higher PQ worlds (minimum 12) that can support a farm and several morale buildings while still having lots of econ buildings. However, money planets can be made based on need as well, if you're running low on cash. I only build 1 farm, unless the world is PQ20 or better, in which case it can afford the extra morale buildings necessary to keep it viable with 2 farms. I don't usually bother with starports on these worlds.

Production worlds tend to be mid-grade in quality, PQ 8-12. Just lots of factories and a starport.

Tech Worlds tend to be smaller in quality: PQ 6 or less. Since I'm going for Neutrality by default, NLCs will be available. That will allow me to make better use of the available terrain.

Wow, thanks for all the replies. I've been using lots of this advice and it has really improved my game. KzintiPatriarch's post was very helpful. I still have to read the last 2 posts. I think I'm good enough to go to the next difficulty now (yay!). Let me read the next 2 posts. Someone should sticky this - lots of awesome info here.