Okay, so I expect an immediate [-] from this bad boy...
Imagine a game built around this model:
1. Short range ships service the planets that they are on only. (for instance, if you want to be a shuttle service on Coruscant, well then go for it.... not so much on Degobah)
2. Medium ships service local cluster and planets.
3. Large ships service the large hyperspace lanes and can travel great distances.
Major pax impact on speed of ships.
News events cause there to be major changes on travel (for instance a starport closure at alderaan)
Rip off all of the Sci Fi genres. Have a cluster of planets for Star Wars, another Trek, another BSG.... Ships from all of these genres as well.
Ship discounts if you have a base in the system that makes them
Lucrative flights are long long long (like 1 route per week to get from New Caprica to Earth) <--- okay, couldn't resist