I, for one, would like to see discussion of LW topics from the perspective of someone knowledgeable about the history of law; after all law is humanity's main attempt to formalize morality, so I would expect some overlap with FAI.

I don't mind people who haven't read the sequences, as long as they don't start spouting garbage that's already been discussed to death and act all huffy when we tell them so; common failure modes are "Here's an obvious solution to the whole FAI problem!", "Morality all boils down to X", and "You people are a cult, you need to listen to a brave outsider who's willing to go against the herd like me".