That is an interesting setting, I went for an after war vs demons world where resources are scarce and humans are fighting for survival with demons still lingering and now great armies of undead are marching from the mist marshes led by 7 fallen lords, the undead having their own society, rankings and aspirations.
Sadly not as based as yours. I also do not have orcs and elves and dwarves are very rare with all player characters starting as human until they reach dwarven or elven enclaves, then they can roll new characters if they want.

The only based thing I went for is cultural homogeneity, the importance of family and merit. Nothing like impending doom to bring families and communities together.