That's really the crux of it, right? There's been extensive discussions about space legs all over the forums, and it's a difficult one to answer from our perspective. It's something we really, really want to do.... but if it doesn't add any long-term value, it's a lot of work for something that lacks meaningful gameplay. There was another thread on this that we were taking notes from with regards to the comparison to EVE's version of 'space legs'. Unfortunately that thread was lost as the OP requested his account to be removed and all posts he made to be wiped. Essentially it was a discussion regarding the feature being removed from EVE (if I recall the linked article correctly) due to lack of people using.
It's still something we'd like to do, but the focus after 2.4 will be improvements of core gameplay mechanics. To add this rather heavy feature without meaningful activities around it would be a disservice to you guys, and it's a hell of a lot of work for the dev team. My advice would be to work on the assumption that it'll be a ways off yet, because as has been mentioned many times before: to do it properly would be a whole new game within ED.
IMO the only thing that you can do is to make simple yet strategic use of areas that you can walk around in. For example another aspect would need to be added to the game. Maybe people could have a salvage/flee market style shop that they own. They can purchase upgrades for it and change the store layout. They can then supply these shops from gathering salvage and or providing trade goods. While this can be done in a private instance, once they leave their personal store it loads back to a public space.
In the public space you could have cosmetic clothing stores, Weapon stores, and Plastic surgery/body modification shops to visit. They could have Pubs with mini games like darts, and or video poker. Inside the pubs they might get access to shady contacts who give them questionable high paying missions. They could add Easter eggs through out the odd bits of the star ports and once you collect enough you get some sort of cosmetic reward.
Basically some cosmetic stuff not available in the store should be able to be gotten inside the game. WoW has done this with great success. They do business like gang busters for store pets, but some of the most coveted pets can be found in the game. Same concept accept apply it to ship kits, decals, paint jobs, or character modifications.
On station you could sneak onto another persons ship and actually steal it. You could also just find the most valuable stuff in their hold and jettison it out of the cargo hatch to the friend who interdicted the ship.
On station you could take part in something like heists in GTA V. Instanced small group actions against, banks, or rare goods locations.
On station you could own a plot of land in the ring and farm/produce various rare items. Then defend said production from a wave style onslaught by NPCs, Horde Mode from Gears of War.
On station apartments and home furnishing. Customized living area that can be visited by friends.
Perhaps data theft and or setting up taps all over the station. Maybe setting up an area in the station and creating the right kind of situation in the system that allows new contacts in the station. Example is bringing a black market into a station that doesnt have one already.
There are lots of things, however it just depends on how much you are willing to design and how much can the engine handle.
EDIT:
In your words it would need to be another game inside of ED and that is correct. Honestly look to GTA V for some inspiration. See Harvest Moon or Payday the Heist for other bits. When it boils down to it. All these games are at the base level are resource management sims. The Resources could be land, money, crops, slimes, whatever. Then you process said resources and get a randomized positive result for your time. As long as its interesting people will continue to push the feeder bar for more pellets.
