Friendship Quotes in The Paladin Prophecy

The word choice is interesting sometimes, because Frost often writes "roommates" instead of friends. Why does the author make this distinction?

This is a sweet little speech from Brook to Will—but why does she think Will's life should be "filled" with friends? Does Brooke value quantity over quality? Or does she mean something else by this statement?

For Will, who has been taught not to trust people for most of his life, trust seems to be the primary criterion in choosing a friend. Actually, given the reality of his situation, that's a pretty good criterion.