First, what's your general opinion about the Space Outposts of the Space Ages?
In general, I think having an outpost is a great idea, but I'm not a big fan of the execution. The main problem is that the outpost are very 1-dimensional, and for the most part inconsequential (or even detrimental) to your progress through the age. Players in those ages can produce all the goods they need for the technologies through their regular city (CF, HC, SC, Event Building, Special Buildings, GBG, etc..), and if you want to produce goods in your outpost you have to spend special goods, which might slow down your ability to progress through technologies.
So if you don't need the outpost for technologies, there is not much else to use it for. You need it to gather credits for the map, but they are very easily produced and stockpiled. By just logging on once every now and then I have 1M+ credits, could probably have been 10s of millions if I actively used the outpost. There is no way to spend those credits, so eventually you just ignore the outpost entirely.
Of course, after you have completed your technologies you can use the outpost to produce extra goods, but by doing so you're again depleting your special good resources, and if the current ages are to go by, you'll need a lot of special goods for future technologies. Why waste special goods, which are hard to get after you leave the age, on goods you already have 10s of thousands of?
When it comes to the buildings and city planning, you really don't have to do much, you can't go wrong. You'll have an abundance of credits so you don't have to worry about maximizing them, and if you want to produce goods you're bottle-necked by special goods production, not by figuring out how to maximize your number of goods buildings. Life Support is also for the most part meaningless, spending a few extra resources when you have 100s of millions or billions of resources doesn't matter.
So to sum up there is no real incentive to focus on the outpost, but if you do there is no strategy to it, you just build whatever fits.
Second, how and for what do you use your Space Outpost?
For a while I used it for goods production, but for the last few months I've just ignored it.
Last but not least, which buildings do you usually build, and for what purpose?
Honestly, I couldn't tell, don't think I remember a single building name. I remember well building names from ages I haven't been in for ages, but I have no idea what the outpost buildings are called, I think that goes to show how little I've focused on the outpost... But either all residential buildings for credits, or max population/tile residential buildings + the goods buildings I have boosts for.
I don't quite know specifically what to change, but for the future ages I really hope the outpost matters for your progression through the tech tree, and that you have to actually think about how to maximize your outpost. One example could be to borrow the idea of separate units from the Egyptian settlement, so perhaps you have to get separate units in the outpost that you need to use for special goods production. Perhaps a bit too disruptive, but I'd like something to make the outpost necessary for progressing through technologies, not just a potential convenience. The credits system is one step in that direction, but it's not enough to make the outposts engaging.