MrFURB I have to disagree
There aren't needed many restrictions for this system. Stations would be needed to be built with 1x2x1 space in front of them, beds would require 2 blocks with 1 block 2x1x1 space above them and that's it.
If players would build stations or beds which aren't accessible for the NPC to walk in front of them, then NPC would not get there and won't work. If corridors would be too narrow, causing NPCs to stuck in them, then player would need to make them wider.
The most problematic factor would be path finding for crew members, but it would be a problem even without this system.
And again - i do not want to order players to build huge interiors in their warships. I know that the priority would be to place system blocks, not decorating the interior, but this idea more or less balance interiors not existing, with dense stations and bed and with plenty of space.
Ships without the interior would have more blocks, wouldn't be sensitive for loosing crew/stations and wouldn't require gathering crew but would have lower stats. Defending this type of ship against invading groups would be nearly impossible.
Ships with dense interior would have the best efficiency, because they would have full potential (no stats debuff) and wouldn't waste space, but also would be sensitive for destroying stations/bed, so critically injuring them would be pretty easy. Invading this ships would be relatively easy, especially after critically damaging the ship.
Ships with bigger interior wouldn't have as good stats as the ships without or with little of interior, but could last longer in battles, because destroying many stations would require destroying much more parts of the ship. Also they could have surplus of the NPCs/stations. Invading party would have a hard task when trying to fully seize the ship.
And You've mentioned additional things to interact with while on ship while in astronaut mode, which is part of the extended idea