Social psychology and sociology, individual and group behavior.
Take the biological and psychological technology in Appleton and layer on sociology and economics, incorporate the magic energy from Ramsgate to form guilds: traders, thieves, wizards, farmers, merchants. Create families, biological imperatives, honor systems, and create motives and goals that span generations.
This is obviously going to be very complex. We need to handle a lot of emotions, perceptions, expectations, things like that, have something like events that are based on that.
Imagine sitting in a tavern, nursing an ale. A man comes in -- a courier -- and sidles up to the bar. He informs the tavernkeeper that a mutual acquaintance (call him "Steve") has made a bet that he will seduce the tavernkeeper's young daughter. The tavernkeeper explodes in anger, takes a weapon from under the bar, and exits to find "Steve".
That's expressible, I think. It's the breadth of what needs to be implemented, not the depth, that make this a challenge.