And Ofelia's punishment of "action" actually corresponds to "gluttony." The nature of the sin of gluttony is the craving for comfort, pleasure, lack of ambition, and wasting one's "possessions," indulging excessively in something or some affair.
As a Prince of Dennisiowa, he had long been aware of the corruption within this nation. Yet he was obsessed with music, devoting all his talent to it... and at a time when the country needed him the most, he chose to board the treasured ship Silver, forgetting all troubles and embarking on a joyous world tour.
His nightmare forced him to confront his own talent and responsibility—to become a King and give up the path of music he loved most, only then could he save this world. Otherwise, by his own power alone, he could not contend with this hollow and icy cold world.
...Speaking of which.