I always thought the docking rings were there to give specific entry and exit vectors for ships. These corridors prevent any collisions from happening. Either from other soace craft or the local terrestrial air transports.
I do think the there should be separate docking areas for unlawfuls in planets. Makes a bit of sense that they could have some way of approaching a planet and landing. They would lead to a seedier side of the planet with a new bar, equipment dealer and comodaties broker. Although I think the problem with that is the planets can only be set to one faction owner. So...kills that idea