I must say, I love the inclusion of the corporations. It's a great strategic twist and is especially helpful in the early game.
However, the IR is often getting shafted as Kuat isn't in Imperial hands at the beginning of most of the GCs. This means they never get KDY, while Mon Calamari is always in NR hands, as is Syca, so those corporations are always in play for those factions.
I'd like to recommend that the KDY Corporation be given as a one time bonus for capturing Kuat, assuming it doesn't start in Imp hands. Forget the shipyard capture bonus, just give the Corp as a bonus. This would make taking Kuat early a critical factor for the IR. The same could be done for the NR and the CEC corporation on Corellia.
Also, seeing as how the NR get two corporations, how about adding Sienar Fleet systems? This would also allow for the addition of another planet, Lianna, where they have their HQ. If you add Sienar Fleet systems and Lianna, that could be a system the IR ALWAYS starts in control of. Or you could base it on Corulag, where they have their advanced research division. Sienar could offer bonuses for TIE Defenders, Scimitar bombers, TIE maulers, TIE crawlers, and the Immobilizer Interdictors. (All info gleaned from Wookiepedia, I have too much time on my hands apparently...)
EDIT: Oh and Sienar also made the Vindicators, so that could be another unit for which they offer a bonus...