1. Magic, Dreams, and the difficulty of love are all themes
2. The tone changes from being Dark and serious to a lighter more humorous mood
3. The mood is the atmosphere of the story, while the tone is the author's attitude towards the topic. You can identify both by looking at the setting, characters, details, and word choices.
4. The Fairies represent mystical imagination and magic and symbolize a sense of escape from the practical world and society.