Questions from The Revelations

Here's a few questions from my book that I forgot to put down for a while now.

What is the reason for the name of The Revelations for this section of the book?

How can Nathan Price not care about his children's safety of staying in the Congo?

Does Leah still hold her father's view of the Africans being savages to be true? Or has she changed her opinion?

What was the importance of Adah's last chapter where she describes Methuselah's death and says at the end: "Only feathers. without the ball of Hope inside. Feathers at last at last and no words at all" (186).