The idea is very clever to include a scene where Prospero himself writes in a fit. It suggests that perhaps when Shakespeare himself wrote the original play, The Tempest, that perhaps he intended it to be a story about his relationship to his community as an outlandish artist with prophetic genius. His writing certainly made him something of a freak in his own time, but as the play well suggests, he is both a primal wizard and royalty.
The royal element of the plot is superfluous, technically, because the characters are not in Italy. They are on an island, crash-landed. There, Ferdinand's folks have to deal with a serious dilemma: Although they betrayed the duke of Milan, Prospero himself, Ferdinand wants to marry Prospero's daughter. They don't know that Prospero's own magic caused their tempest, and the plot suggest here that Prospero did not know what exactly he intended in his own magic.
The story seems to suggest that, although Prospero has to work through hatred about his unfair ejection from society, his being ostracized from community as a castaway, as a freak—although he and Ariel make this point quite clear, the story bends back into favor, and Prospero finds patience and forgiveness, and he understands that his royalty has not been taken away from him, except unless he forbids his daughter to marry back into the royalty of Italy. In the end, the marriage restores him to a place a royalty, suggesting that his true royalty comes from forgiving his enemies and cleansing himself of hatred.
