Fighters can already repair themselves if they have sufficient MSP
Can they? I had a damaged fighter that should have enough MSP to fix itself orbiting a planet for PPV for maybe 30 years before it was visited by angry NPR.
It was still damaged when I was making stock of my forces in the system before battle. It was being fully maintained and had MSP whole time.
My guess would be that you need a Damage Control Rating of 1 or more to repair. You're unlikely to have a full 50T engineering space on a fighter, so most of the time you need the hanger to provide a bonus to the DCR otherwise the chance of repair is 0.
Regarding the Deep Space Population feature, I note that it uses the same acronym as the game Dyson Sphere Program.
There will be no surface location to place installations, ground forces, fuel, ordnance or MSP.
Without ground forces, how can we deal with unrest?
Due to the lack of a physical location, no ground combat can take place at a DSP, although any ships or stations at the location can be attacked via boarding combat.
If you capture an orbital habitat, what does that do to the portion of the population that depends on it?
Minerals can be delivered to the DSP and collected from it, as it assumed these are stored as free-floating resources.
This feels a little odd, I think the main thing is it feels discordant with the prohibition of storing fuel, ordnance, and MSP. While it seems possible for raw minerals to be kept in blocks floating freely in space, they ought to be in orbit of the star. It also implies that exposure to vacuum or solar radiation doesn't cause the materials to degrade in some way. I'd also be concerned about organization, access, and handling in the absence of any infrastructure.
The current rules make things simple, and that's probably for the best, but if you changed it so that minerals need to be stored on a ship/station with cargo space I think that would be entirely justifiable.
Orbital habitats can be built at, or towed to, the DSP
How can you build a habitat at the DSP if you can't have construction factories and a spaceport at the DSP?
Deep Space Populations do not orbit any stars. They remain in their original position.
Various comments regarding cryo storage for habitats
1 orbital habitat contains 200k people and takes 500kT of space at a cost of 200 BP
20 cryo transports contain 200k people and only takes 50kT of space at a cost of 1000 BP
I'd be more worried about the cost of adding cyro storage to a habitat than the size.