Another thing is Life support. How are these grossly overloaded ships able to sustain life support for all of these people? WHERE is the air coming from?! How are the ships cleaning the air fast enough to sustain them?
And another thing: how can an exterior "hab shelter" be safe at all to travel in? with how quickly these things have to be built, they aren't going to be armored. That means a single piece of rock or scrap could puncture and either kill the occupant(s) directly or indirectly
Re: Life Support. You're in a debris field with several more or less intact but inoperable ships floating around. Surely there are a few salvageable life support components in there.
Re: Safety. You're in a debris field with several more or less intact but inoperable ships. Think you might possibly be able to find some more or less intact hull sections to turn into your shelters, or some more or less intact escape pods pulled out of destroyed ships and patched enough to be livable and then grafted to the hull in some way? Or perhaps even a relatively intact hull which can be restored sufficiently to support an atmosphere, heat, and inertial compensation and then towed along? Also, indications are that at least one type of cargo ship in Starsector uses cargo containers which are at least partially exposed to space. The Atlas description, after all, mentions pirates disabling a container's couplers to steal it; this wouldn't make a terrible amount of sense if they have to cut through the Atlas hull first, implying that the cargo containers carried by the Atlas are at least partially exposed to space and should therefore be able to withstand micrometeor impacts. Reinforcing something like that a bit to better protect against debris impacts and sealing it up to hold heat and an atmosphere is probably a lot less work than building a habitat from the ground up.
More to the point, it's generally idiotic to remain floating in space and hoping that the next ship that passes by notices you and stops before your spacesuit or hull fragment or escape pod runs out of power, water, heat, air, whatever. You know that there's a ship here now that's willing to rescue you. You don't know if there's going to be another before your time's up. Even if another one comes by you don't know that it's going to notice you. You are drifting in space; right now, you're in a debris field which will tend to draw scavengers, and you're relatively close to at least some operational ships. That debris field is not going to stay together all that long, though, and there's no guarantee that you're drifting with the pieces of it that are attractive enough to draw salvagers, and one or two humans are not a particularly visible target.
Big difference in space and the ocean my friend. I wouldn't have to worry about getting shot off in that kind of situation where you would have "hab shelters" as most likely the boat would have sunk or been unable to handle so much weight. Not to mention how bad one ship would look like to its home country's people if they fired on another ship that was rescuing people
You think a ship would be thought of poorly by its home country's people for firing on ships engaged in rescue operations? History doesn't agree with you. In WWI, three British cruisers were sunk in the English channel by a single German submarine in a single action, with the second and third cruiser being sunk after stopping to drop boats and pick up survivors from the first cruiser. The commander of that submarine was awarded a medal. Allied aircraft in WWII bombed a German submarine which surfaced and attempted to give aid to survivors of a ship that it'd just torpedoed, and I am not aware of any repercussions for the pilots and commanders who made that decision. Submarines have been known to use lifeboats as bait, lurking under the waves and torpedoing ships that come near to try to recover survivors. Convoys were to keep going despite the potential to rescue survivors of torpedoed vessels because the expected act of a hostile warship that attacks the convoy is to keep attacking the ships in the convoy, whether or not they stop to engage in rescue operations, and so stopping and making yourself an easy target is the stupid thing to do. Fleets in action with one another do not generally allow ships to break off simply to go rescue survivors from sinking ships, nor do ships routinely engage in recovery operations in the presence of the enemy; the survivors generally (but not always; sometimes a low-value vessel might be allowed to break off, or a supporting vessel following behind will arrive but isn't thought to be needed for the main action) need to wait until the action is over before ships begin to engage in recovery operations.