I'd like to see a way to set a destination, and "ask" the mission boards for missions near that destination.
Basically, rather than me going out and saying "Hey guys, I have a ship with a cargo rack, who has cargo that needs hauling?" I can say "Hey guys, I'm going out near xxxx, anyone have any business out that way?" Those can even pay less, with the rationale that since the customer isn't asking upfront, it's probably a lower priority for them. It would add a lot of interest to the whole "mission runner" side of things though.
Would also kind of be cool to expand on the "mission offers pop up randomly when you're in a RES" thing they have, and have missions pop up when you're mining, bulk trading, or smuggling - offering to buy your non-mission cargo at a specific destination for a bonus price.
I'd like to see more mission destination endpoints that aren't stations. If you're doing something shady, maybe you'll drop your cargo off with a cargoship in USS, and you'll even see them deploy collector limpets to pick it all up. If they can get a working planetary navigation system in place, you can have missions where you drop off cargo at POI-like randomly generated mini-bases or mining facilities instead of a full-on starport. Can also work for passenger missions.
That could also make for more interesting multi-part missions. For example: you're supposed to haul some cargo to a POI mining base, but when you get there it's been destroyed. If you sort through the materials strewn about though, you can scan a datapoint that gives you, say, some recorded intercepted communications of the attackers. If you take that to a science or military outpost or something to get decoded, and you find out what faction did it. Then you'd get to choose which faction to support from there - get some revenge on the attackers, or turn on your original employers for the delivery mission. Since both of these minor factions invested a good bit in this operation, the reward (aside from credits) would be a larger-than-normal influence bump. Something like that would add in a lot more flavor to both missions and playing the BGS.