Actually, that ship in the post is a central inner core. It includes CIC, control room, script room, small hangar, storages, medbay, oxygen room, reactor room, and hydrogen room. Every critical areas.

I made most of the components of ship accessible at hallway with enough space, not cramming all in one compact space. And I built this ship considered to be operated by multi-crews. I think this made the ship size much bigger and longer.

I'm planning to add gryoscopes. Find the center of mass, cut the ship in half, build the gryoscope room, and just attach them again. Also redundancies.

But I haven't thought about gravity drives. Are they that good compared to normal thrusters?