We haven't had a major character of consequences die in some time.. Especially anyone on "Team Harry," who's death sends out serious repercussions for the rest of the series...
Winter Court...
1] Mab, a big one, if she dies, Molly becomes Queen... Big ripples..
2] Mother Winter, Mab becomes Mother, Molly becomes Queen, bigger ripples..
3] Lea, might hurt, but in my opinion not that big a deal.
We know Mab and Molly are for sure off the table: they appear in Christmas eve as Winter Queen and Lady, and that's set after Peace Talks. By extension, since they've kept their positions, Mother Winter is still Mother Winter.
Lea is an interesting option.
The White Council..
1] Eb, yeah it would hurt, but ripples not huge
2] Listens to Wind, again like Eb, ripples not huge that goes for the rest of the Senior
Council with the exception of two..
3] Rashid, huge impact because he is the Gatekeeper, often the swing vote on the Council, also
he appears to be a major general in the fight to keep out Nemesis etc at the Gates, we have
no clue about just what he does, his death would be major...
4] The Merlin, mainly because of the power vacuum his death would create and the power struggle that would follow..
I think that LtW, Eb, Rashid, and Langtry each have 60-40 odds of surviving: any individual one is less likely to die, but I'm betting on a Senior Council level death curse, and we haven't seen Martha Liberty or Ancient Mai really go all out yet. Any one of the SC dying is going to have huge ripple effects, especially since Rashid implied in Turn Coat that Harry is going to confront the White Council at some point in the future.
The White Court..
1] Thomas, for all the obvious reasons.. But he'd mainly matter to Harry, but ripples beyond that? Doubtful...
2] Lara, now her death would really stink up things..
Speaking from a storycraft perspective, Thomas is the main person with a target on his back from where I'm standing. Remember, we're not reading the books from the perspective of "what is the thing that is most significant in the world", we're reading them from
Harry's perspective. Lara might die, but I'm going to give her 70-30 odds of surviving: she's pretty slick, and not inclined to slug things out if, say, Mab decides it's time to stop being nice and start raining unholy terror on everything.
Murphy, her death would cause a lot of personal pain for Harry, but her place in the universe is small...
Much to your chagrin, I think Murphy is the one person most likely to survive this mess other than people who have already been confirmed. She's almost certainly going to be involved, but in more of a coordinator of the Paranet role than a kicking ass role: I don't think JB is the type of person who's going to completely sideline a character with as imposing a presence as Murphy just because she's physically injured: he's made clear that he does NOT think that physical power is the be all end all of influence.