The Theme of "The Sins of Prince Saradine"

You said that this month's topic was "The Sins of Prince Saradine." Well, here's my discussion of it. Please criticize and even contradict.

“But only slightly less well-known is ‘Never trust a Sicilian when life is on the line.’”
----------The Princess Bride
Despite the fact that The Princess Bride is incredibly Chestertonian, despite the fact that this quote is good advice, and despite the vengeful Sicilian, this quote is not the main theme of “The Sins of Prince Saradine.” What the story focuses on, however, is that sin requires punishment. And the unpunished sin is quite possibly the worst of all.
The very plot of the story brings out this theme. The Sicilian, whose sin (although it is not the smallest) is the most human, receives a relatively light punishment, the punishment of the state. The prince’s brother, whose sin is less sympathizable and less serious, dies as a result of his love of money. The prince, however goes unpunished for his sin of deception and double murder. Yet, he leads a miserable most of his life hiding from the vengeful Sicilian. Most importantly, the image of the sly double criminal smugly enjoying his own possessions when he should be enjoying the comforts of jail leaves the reader rightly puzzled, fascinated, and inebriated with a sense of the lack of justice. As a supplement to the plot, small details such as the prince’s psychologically crazy mirrors and the maid’s mysterious allusion to the fact that the good brother is not really the good one add to the sense that the real prince is a whitewashed tomb filled with unsettling decay. By the time Chesterton is finished with us, we want justice and realize its necessity. Hopefully, however, we will not go the route of the Sicilian--or Domingo Montoya.