You can infer the author/illustrator is not fond of getting a college degree since they are metaphorically saying it does not equate to a well paying job
It takes place in Macbeth's castle
A theme could be to never give up and have couage and a clear example of this theme can be with the main character herself. Poppy never gave up and with every challenge she went through it bravely and showed everyone that she was brave.
You should fine certain quotes to back up this theme, so you can have proper evidence.
Simple and complex and the two types
There's different opinions so you'll be able to focus on the good and bad parts of your rehearsal.