These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Ditto with Miranda and Caliban. Some versions imply that Caliban didn't rape Miranda, but just got caught having a torrid affair with her.
Also Caliban- nasty brute or Noble Savage? Also, his appearance has been much debated with interpretations ranging from some kind of ape man to a fish person, to a normal, non-white human.
Prior to the events shown in the play, was Prospero a wise ruler who studied magic on the side, or was he just a deluded old man who cared more about magic than about his family and responsibilities? Is his antisocial personality the result of his righteous anger at everyone who wronged him, a byproduct of his years of isolation on the island, or has he been that way ever since he took up magic?
Viewer Gender Confusion: Ariel. In the text, he's male, but he's also a fairy, and most modern English speakers think Ariel sounds like a girl's name. He is most likely supposed to be androgynous, and is as often played female as male.
Ariel isn't necessarily a fairy. The name "Ariel" could mean "airy," as in the element in which Ariel lives, but it is also Biblical Hebrew and means "Lion of God." Unlike Puck, it's not entirely clear WHAT Ariel is (ditto Caliban).