Alright...tons to reply to...first I'll do Erik...
Is it possible to build a positive-income Gal Station? Living/Commerce looks that way...
Secondly, I really wish for hybrid stations. Why have 4 types? Just make a template and allow different modules to be added, or use the module space for living quarters and trade booths et al.
I really want these "minor planets" with a few turret modules and some income. My way of playing.
1) Yes, you will be able to construct Positive-Income Gal. Stations. Living colonies are just that.
2) Because a blank-slate Gal. Station would have no basic advantages. An unenhanced Support Military station will have a few small turrets to add to its strength, and Defense Military station has added armor plating, etc. I could [and probably should] add a blank slate one, but be aware it would have no added advantages and be basically worthless until upgraded.
Exactly what is "improves economy" ? I'm Merchantile, starting with Basic Commerce (which, by the way, does exactly what?) and if I research Energy Banks at the start, how exactly does this affect me?
IMO the tech interstellar trade should require interplanetary commerce, too.
3) When a technology "improves economy", it adds strength to your economy. Like in most NESes, doing things like creating currencies, building special inter-empire trade routes, etc. will enhance your economy slightly. However, when a tech has that in its description, it is a lot more powerful. As such, a Merchantile civ starts with a naturally stronger economy, is on the verge of having one thanks to Basic Commerce, and will go up to Growing after researching Energy Banks and be 1/4 of the way to the Booming economic status -- and this is not counting those little projects. Normal civs will barely reach Growing with Basic Commerce and Energy Banks even with those projects.
4) Interplanetary Commerce represents the development of a good, well-balanced, single-government interplanetary commercial system. Interstellar Trade represents the creation of rules and regulations, and some other things that you can imagine for yourself, for [then unregulated] trade between planets in your empire.
Continuing with more stuff I thought of... how much influence do I have over my starting position?
Does race background have an(y) effect?
5) You can pick your own Starting Location at the moment.
6) Race backgrounds themselves actually help me determine how the citizenry of a civilization may act to other races, civilizations, ideals, etc. Regardless of what the government does, citizens may ridicule a race, become violent because they're different, etc. History and culture says a lot about how these things can happen and will have an effect on foreign relations, trade, etc.
(I'm imagining a 3D tech tree over here... I must be seriously insane.)
Can we assume VCCs will default to success in the early phase, since we really don't have the money for PCP's?
Yes, you are insane.

Just kidding. I added color, though.
Yes, VCCs are default early on.
Is there any limit to models? I advise the system from MoO: A race may only have SIX ship designs at one time. When a design is scrapped, so are all ships of that type, and one may only build from the six designs one has. This would pre-empt a lot of paperwork on ship models while creating an interesting tactical flavor as players wonder what to do with their "slots". (Hmm... one scout, one beams fighter, one missiler, one transport, one heavy bomber...)
That's actually something I hadn't thought of. It makes sense, but I'd make the number a little higher, maybe 8. There are many chassis I have planned to add in...
Edit for more:
Conquering Planets. Sure, I may have orbital superiority, but where are the boots on the ground??? Will you keep track of troops somehow? Because I really dislike the idea of "Okay, you shot the enemy fighters and satellites out of the sky, the planet surrendered."
Troops won't really be kept track of. It'd be incredibly hard for me to on this scale. When one captures a planet, the GOVERNMENT has surrendered. The citizenry may or may not have. Rebellion and insurgency is very likely to occur. However, there are ways to alleviate this, both "evil" -- forced reeducation programs, orbital bombardment of enemy weapon storage facilities AND civilian areas, complete genocide of natives, etc. -- and "good" -- granting limited self-government [EFFECTIVELY], allowing free education, stopping rioting and crime sprees, and other such things. A display of force CAN work, especially on Agricultural and Developing worlds. Minor Races are especially vulnerable since they're...well...highly primitive.