Guilt and Blame Quotes in Mortal Engines

How we cite our quotes: (Chapter.Paragraph)

Quote #4

I killed Grike, [Tom] thought. All right, so he was dead already, technically, but he was still a person. He had hopes and plans and dreams, and I put a stop to them all. (24.12)

Grike is the first person (or near-person) Tom kills, and he feels bad about it. Considering that Grike would have killed him given half a chance, is Tom being unfair with himself?

Quote #5

"I supposed I should thank you for saving my life, too." (26.12)

Looky here. Little Miss Angry Pants, a.k.a. Hester, feels a little guilty for blaming Tom for saving her. While it's not quite an apology, it'll have to do.

Quote #6

If Hester killed [Valentine], Tom would have betrayed his whole city... (28.4)

Tom even holds himself responsible for other people's actions. Are Hester's actions in any way under Tom's control, and should he blame himself for any of this? Tom seems pretty conscientious. What does this tell us about his actions in the novel? Is he more like Hester or like Katherine?