I'm not entirely sure that military rank would be anything more than a different type of Obligation.
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.
I'm also expecting rules to make combat checks harder in melee - rather than a difficulty of 2 for melee combat, it be modified by agility or certain talents (this would work for lightsaber combat as well - each form being a talent tree like each force power).
Also, I'm expecting lots of rules for co-operative characters, such as the party being the member of a fighter squad - so talents that give bonuses while in formation, etc.
You're going to find that many of the truths we cling to depend greatly on our own point if EU.