I understand that many of the facilities in the rules pages can be built by the average player in their city. Some provide an income, others don't. Some allow access to services such as GNS posts, Markets, NPC travel, etc., etc.
Can an individual build and operate any/all the service-type buildings?
For example, can an individual build a Starport to provide a destination to players using the NPC travel service? Or is that only available to factions? (And more specifically, Travel factions.)
What about a Commerce Centre, to access the Market?
I realise that not all of the service-type building will provide Facility Income, but if you were trying to achieve maximum versatility and function in a player owned city, what can you (and can't you) build?
If you go to the expanded view for each of the faciliites, it will give a list of factions that are affiliated with it. You will have to hop to one of these factions ot build. If there are no factions listed, then you do not have to be in any faction to build it. However I think there may be one or 2 7x7 facilities that have no affiliation and still cannot be built.
As for the NPC transport since you mention it, only faction owned, transport faction managed starport will allow members of the owning faction to use NPC transport there - no-one else. Transport faction owned starports allow travel to them from NPC starports and their own starports, and to other owned starports. Persnoally owned starports I do not believe can use the NPC transport function, even if assigned to a transport faction.