Because the stations in SS3D are user-created, they may be highly diverse in their shapes, sizes, and arrangement. Despite this, stations will likely share many similarities.
The first and most important thing to note about stations is that they truly are surrounded by the void of space. Therefore, stations must be equipped with facilities that allow the station to be inhabited by human life, such as:
Atmospheric supply system (network of pipes & machines).
Facilities for growing & cooking food.
Places for crew members to eat and sleep.
Places for emergency and medical treatment of the crew.
Ports for cargo & arrival/departure shuttles + emergency pods.
Sustainable electricity & gravity generators.
Work stations to perform tasks for NT (?)
Station designers may take great liberties in designing the placement of these systems, but they almost certainly must be present.
Additionally to the life-sustaining aspects of the station, it’s important to remember that the station is filled with work environments, where specific sectors have restricted access to specific crew members. Medical doctors probably don’t need to be in the hydroponics basin; cargo workers probably shouldn’t be dwelling in the armory.
Because of these factors, all crew members are equipped with an ID, which almost all airlocks in the station should be programmed to respond to.
A crew member without an ID may be heavily restricted by where he can go, as doors will simply refuse to open unless they can prove they has access. IDs may also serve the purpose of locking specific equipment, such as lockers & briefcases, to prevent other crew members stealing one’s equipment.
Unfortunately, most things on the station are breakable. This includes the structure of the station like airlocks, walls, floors, and windows. These can all be broken with possible devastating effects to the station's ability to sustain life, like sucking out the atmosphere if an external wall is broken.
However, all elements of the station can also be rebuilt or added upon, using a wide range of raw materials and fabrication technology. And as long as you have the gases to do so, you can repressurize the station if needed.