2)Logistics/Tactical -
I second someone else above, who pointed out that the distinction between these is pretty silly - why not just have a given number of spots to build based on type of planet?
I guess the potential reason is that it could be too unbalancing or make logistics deemphasized? I think it would be fine - you could put in max numbers of particular installations for balance I guess.
I think it would be improved to have a much more limited are in which you can build - ie for the outer reaches (1/3-1/2) of the well to be unbuildable. Or just make the gravity wells 2-3 times bigger (more on this later). It doesn't make a lot of senes to me that you could build in what starts to be deep space and it be useful, logical, or possible to defend.