Dem I predominantly agree with you, it is personally generally an undesirable mode of making things fit for me to wash away Canon characters, I agree to it here solely so that we can all have our characters doing what we want them to and placed where we want them. Should whoever controls NR want to retain Mothma, Ackbar, Luke, Leia, Solo etc, and merely pen themselves in alongside ans use those characters as they desire (albeit within general anticipated traits of their character), this would make me most happy, however given that I not controlling NR in III, I am happy to allow Hale to do whatever he wants/needs with it/them. My personal pref would be to see Canon Chars retained and hold posts, but it's well outside of my realm of justified story control so I leave it up to Hale to fulfill his desires/needs.
The Killing of Leia, Solo and Chewbacca for ME as a Faction/Character Story Angle are tied to their affronts against Jabba, especially Leia killing him. To kill a Hutt is an absurd concept to a Hutt, and is never ever justified or deserving, so Hutts collectively want her head as an example. You don't kill Hutts. However, it's not necessity for me for her/them to Die, all I need is an encounter with them at Coruscant that occurs between the lines of the grander battle raging on. Maybe the Falcon get's destroyed, Maybe Leia loses a leg or some shit. They don't have to die for me, I just have to encoutner them with some hutt agents in the mix so to speak to bring that angle to a semi-climax.
If this is to be entirely reconsidered, I am entirely fine with Canon chars surviving. Whatever each player needs to allow for them to fill/occupy the space with their characters they want to in III I am in favor of.
RE: The other subject Dem touches. It sounds like an advocation of the factions themselves existing as NPCs, and us as players merely occupying a space of influence/power within those factions, having only limited main line char influence, i.e. if you serve NR, your char occupies some space within NR and doesn't direct the NR direction as a whole. I like it, but we somehwat use that in that a single player controls the whole faction so single player controls all potential chars in a faction, meaning that I may control Hutts in III which means the authority of the Grand Council of Elders, but if a char I'm using is more so a field commander, I'm still somewhat serving the dynamic you speak of, albeit with the wealth of posession at my disposal, though myself I try to generally dispatch things as covered in story premise and in line with a characters rank/post. I think we sort of do that as close as possible without creating the problem of needing a GM to exclusively facilitate the larger NPC action. It's almost a touching a subject that relates to purely how you envision and think about somethign in your head. . .i'm not sure there's a much better way of capturing the dynamic you speak of besides being cautious in how we execute, word and do things and are sure it's tied in to the realm of chars powers of manipulation. I'm all open to hear further ideas on the topic, but off top of my head I think we're as close to doing that as we can.
You could simply have the chars you mainly write about be lower level within the faction that you as a whole control. Then you are only occassionally having to embody to will of the WHOLE FACTION with it's LEADERSHIP, and majority of time is spent executing action at the level of a lesser authority within said faction. I'm just not sure it's possible to get any closer to that. . .it seems to me it's solely a perception thing. I could be wrong though!