The problem is with the AI. They want to attack some predefined object (characters, planets) but this is overcomable. About the GUI, everything can be changed. Even the locations of our fellow friends - the droids. Voices can be changed, locations of X buttons can be changed, the design of menu can be changed, even the droids can be changed in other droid shapes, movings, taunts. Kyp was not in the Thrawn era, at that moment he was a spice-miner . Actually, it should be possible to change the predefinitions of the planets you start with, so you can give some of the planets to Empire or NR, and place shipyards, cloning facilities (I made a cool one some months ago). It is the easiest to change names of Yavin and Coruscant, but then it is not anymore really realistic. The Empire wouldn't know where to find the NR Hq, and dito. I was thinking about changing sites, and instead of the Alliance Hq Cloud City, we could make a Chimeara or spacestation Hq.