Nice analysis! I really like the way you quantified it.

This is off-topic, but I think Death Note is practically begging to be re-written as rationalist fanfiction: Light's manipulation skills could be used to discuss psychology and cognitive biases (much like Draco Malfoy in HP:MOR). L would of course be a Bayesian rationalist, and Soichiro and Izowa could be Traditional Rationalist foils who would allow L to explain the ins and outs of high-level rationality. (As you've shown here, information theory could play a larger role in L's investigation.) The cat-and-mouse games between L and Light could be turned into decision theory problems; the rules related to ownership of the notebook could be used to explore timeless reasoning (much like the film Memento). The story is already brimming with ethical questions, and both L and Light's internal monologues could be used to discuss consequentialism and utilitarianism. I'm not sure what could be done with the rest of the characters or how the supernatural aspect would be handled, but it would probably be an interesting read.