I turn off Mongol Hordes, Turkic Conquerers, Aztecs and Devil Worshipers in rules. I do have all DLC enabled.
One level up from your mod directory might be a Princes of Darkness folder. Delete it. It should be recreated when you start the mod.
I've set it for monthly autosaves.
Ahh... good to hear it was just your impatience. After the first time you play it, flags and the like get stored in that Princes of Darkness folder, so the mod will run faster in the future.
The secrecy-themed "buildings" will come back. The old version worked with the idea of a very low number of troops (dozens and hundreds, rather than tens of thousands). But such low number of troops tended to break the AI. Armies would just stand around in their home provinces.
So, I just have to wrap my head around the idea that those numbers represent "power" rather than "quantity".
Current development path:
1242 AD bookmark will wait on the release of Onyx Path's V20 Dark Age Companion as it has details for India, Somalia, Scandinavia, England, Rome and Holy Roman Empire. It details the domains of Bath, Bjarkarey, Rome, Constantinople, Mogadishu and Mangaluru.
Kindred Knightly Orders, Secret societies, Roads and Paths of Enligntenment as societies, Bloodlines (particularly for Requiem), Werewolf lodges and totems, etc... will wait on the next CK2 patches which improve societies and in particular the "secret member of a covenant", which should be great fun for secret Sabbat in a Camarilla domain, etc...
Now that Dark Eras Companion is out, there are some details for 1142 that can be found, including the name of the Ventrue ruling Constantinople. Also, "Forsaken by Rome" has a fascinating take on a Iron Master-Ivory Claw unity as well as associating certain werewolf tribes with certain Germanic and Slav tribes during the greaty migratory era. So, I could put some work into Requiem.
But instead, I think I will bring back building and perhaps some supernatural units and retainers. I think I also code some mechanical things like NPCs developing disciplines over game pulses.
I could write up more canon NPCs from Dark Ages, but that task could go on forever. There are
183 cities with named princes in Europe, Africa, near east and middle east that we have some details for. But now that I've provided 18 examples, I hope some of other folks stepup and contribute some more of these characters. If I come back to them, I might start with fleshing out characters from the Veil of Night next.