Because Twain's writing is very inspiring and encouraging
True(I really dont know i just wanted to finish the thing)
Personification is a figure of speech in which a thing /an idea is given human attributes.
Here instead of "you will pay the price", the author says "your lives will pay the price", using personification.
She believed paper was more patient than people because the paper listen to what she's saying and keeps her feelings secret. Basically, kitty, the diary, serves as her bestfriend since all the other people living in the secret annex aren't exactly her idea of bestfriends. Hope this help you:)