Answer:
Its actually known that Poe uses the word nevermore because "loss will always be part of life" meaning that we cannot hold onto something we have or who we love. a way of saying we can't hold on.
Answer:
I've not read Farenheit 451, but from the quote I believe it's trying to say "it doesn't matter what you do, as long as you impact it enough to be remembered" or something similar, though again I may be wrong as I've not read the book.
A person can change their opinions/feelings on animals for multiple reasons. For example, they can make friends with an animal or start a relationship that involves no communication (cause animals can't talk) but lots of love. Also, if the animal starts being friendly to the person, there's a high chance that the person may not take their love for granted.
