I agree with Hales points, but also would add that there is at least some simmering of interest here amongst us to begin with.
I think the best jumping off point for any stab at a galactic scale sim with what we know is following. . .
1) Start out with a Galaxy, full routes for traveling- allowing for "trade routes" "blockades" etc in economic terms of game play and other venues of attacking opponents. You make this a good full galaxy with important worlds and few additional back up worlds. Maybe try to limit to 100 or less, or at least near there maybe. To allow for story dynamic to fulfill game purpose of taking and holding territory, I think After Endor suits best, then you have Rebellion in position of strength and possibly early shaping into NR, and Empire can be fractured to allow for the next dynamic..
2) "Players" start out with a base Fleet/Armada, and control/governance of 1 System. Admirals, Moffs, Imperial Governors, Local Governors risen up in Palpatines death loyal to Rebellion/NR, worlds actually a part of NR or indep worlds part of Rebellion now openly in defiance of crumbling Empire.. etc. Various angles for us each to choose. Every other NPC system then has a leaning loyalty, Rebel/Imperial/Indep whatever based on their canon situations at the time generally. They'd also have their own elements of defense, perhaps their Fleets are comparable to what a Player starts with at first, while a Player has more growth potential and an NPC just hovers at whatever it starts at, with certain NPCs of course having more. For instance- we could establish Coruscant as an NPC Galactic Empire entity that Players cannot choose at the onset, it is a goal for a Player/Players in concert together to take it, or perhaps an Imperial Player to gain the favor/loyalty of and rebuild the True Galactic Empire? But essentially a Player can work alone, in name of Republic/Empire/Self, or work together with others as well to build a greater force, or stab each other in back ;p A balance of wide open sim and a living rpg world of sorts.
3) Combat should be as simple as possible with diminutive value sets and if at all feasible/trusting the incorporation of die rolling for variation. The concept of combined fleet values is worth consideration for even more simplicity, but it of course sacrifices some tactical dimension. You can compensate by inclusion of ideas like Fleet Formations which would affect damage dispersal/defense/offense and Focus elements such as what is primary objective that they are trying a little harder at and maybe thus gain a benefit from and conversely in other area a detriment to?- which would be options able to switch from turn to turn/round to round. Ideally, combat would only last 2-3 exchanges until an outcome is decided to keep things moving and exciting?
