being able to occupy/build stations (like the bandits do) would be nice, Even forming a new empire( wich obviously costs a lot, needs a lot of manpower, and makes u pretty much every1s enemie). for the epic battles make a RTS mode, where u could control many ships, in this mode my heroes could work as admirals, guarding my trade convoys, or initaing attacks for more space. Make it available to climb up ranks if i work for an empire or corp , resulting in them letting me protect a system with all the stations, where i pretty much control it, but for the empire. Make it available to actually contact the corporation/empire leaders/representatives to negotiate wars/trades/sharing of technology/alliances/bribes/beneficial offers.
Resources should start to pl;ay an important role, especially in war times, as in blockades to systems, sabotaging/blowing up mines, trading.
Make it so that time passes by, as in with time of playing new tech appears, wich could be bought stolen,sabotaged... different for each corp or emp and at different times.( and dont make it just 1 super ship/gun per corp)
Make it possible to manage population in ur systems( as in training troops to become pilots, ( rookie>pilot>advanced pilot>ace>Will Smith)) make them guard the systems strategical objects, patrol , or attack another system.
and ya more more more more more ships/ship classes/ SIZES / firepower. ( carries with many fighters, drone ships, builders - to deploy turrets , build jump gates, build stations, capital class ships, to take out larger ships/star bases/ fortifications.
if u implement at least half of this, and a half of that half actually works as i hope it will , ILL BUY 2 CD`s
( unless the game will be on 2/3 cds and weight 20GB wich i totally dont mind, ill still buy double )
**edit**
give exploration a different aproach: finding wormholes or anomalys, that could be used to travel to new systems. It could result into u stumbling upon new alien races, that could be agressive or friendly they could be on the smale level /lower/higher tech wise , u could trigger a war with to take their territory or learn something new from them, finding some artefacts that could improve your empire, not only in weapon tech but industrial aswell , wich would make u target of sabotage, espionage and intrigues even simply others wanting u gone.Or simply finding a system rich with resources that u could mine , to produce new weapons/ships or simply trade with.
putting systems ( for example if you dont want others to make contact with the aliens or find some artefacts) off limits, making ur ships fire at any1 who enters.