As to mass combat, I've given some though and I'd like it to be represented by a roll of the dice, Enemy forces represented by difficulty dice, Allied forces by Ability dice and so on. PC's accomplishing specific goals for a mission could upgrade the Ability dice, while failing something could be Challeng dice, etc. Just a thought.
Think of the Battle of Endor, the party trying to take out the shield generator, while the battle rages in space. The rebel fleet had maybe 3 dice, the imperial 5. The shield generator and Deathstar being active upgrades 2 dice, etc. While I haven't fleshed out the idea fully, it could be a good way to have a large battle represented 'numerically' without the minutia of every detail and attack.
This element I think has some really intriguing possibilities; the narrative type of dice for Edge of the Empire could really shine here. I could see a number of different rolls, with the results affecting the numbers on both sides. The Rebels are losing in the first couple of rolls, until an A-Wing pilot takes out the Executor and the deflector shield is knocked out. At that point the rolls become easier for the Rebel side and the tide is turned.
-Nate