Bring on the tough stuff - there’s not just one right answer.
OK, you're the hotshot behind this novel's marketing, and you're thinking of the future. Which character or plot thread would get its own spin-off? Who do we want to hear more about? Who would do best in a spin-off novel? TV show? Which characters could least pull it off?
One of Dickens's tricks for making sure readers recognize and remember each character (especially the minor ones) is to give each of them some verbal or physical tic. Smallweed needs to be plumped like a pillow, Badger is obsessed with his wife's previous husbands, Bagnet doesn't praise his wife to her face because "Discipline must be maintained," Vholes talks in a whisper, Phil walks with one shoulder against the wall of the room, and so on. Switch around some of these tics and what happens to the characters? What's different?
The third-person narrator tends to take a tone of jaded cynicism, while Esther narrates with a kind of intelligent curiosity. Find passages that demonstrate these narrative voices, then try to imagine a narrator switch. How would Esther describe Tom-all-Alone's, for instance? How would the third-person narrator describe Esther and Lady Dedlock's meeting after Esther's illness? How much of the mood of each scene is shaped by the voice telling the story?
Imagine replacing Esther as the first-person narrator. Who else's voice would be interesting to hear tell the story? One of the good characters? One of the bad guys? Are there characters that just wouldn't be able to be narrators because they are too self-centered, too dumb to explain what's happening, or for some other reason?
Which character could easily live in our times with just a change of clothes? Who is least suited to life today? Why?