In the npc tier post I saw a mention of economy alongside faction population. Does that mean there will be some degree of economy simulation?
For sure. At the moment it is slave based. Slaves get shuffled throughout different kingdoms. Then we'll have a full economical loop with money, commodities etc.
How in depth do you plan on making the economy? Will I be able to, say, save a town from being malnourished by selling them enough food?