So I took the liberty of generating a map and getting the AI to AutoPlay for 200t, in case we want to do the first one.
Here's a link to some pictures. I can't seem to insert them. Unfortunately the bottom civ is in a...bad situation. It's Charadon, and he's researching Fishery with +14gpt at 0%. And he has four cities and only 25 units. I was a little worried we'd just end up with the starting civ (as they have Deity tech penalties), but Charadon just loves under-performing.
This is on normal speed, but Cassiel is about to finish Guilds and has five times their score.
(We can regenerate, though. I am a bit worried that the map might be too big, and the turns will get slow too quick. I could also see us letting them run for another 100t so things have settled out more.)
Erebus in the Balance - a FFH Modmod based around balancing and polishing FFH for streamlined competitive play.
The problem with the AI takeover is that it's such a fine balance between having an easy winning position and a hopeless one. The Mind 3 one would be bizarre and interesting, I guess it's my preferred one out of these three. The Perpentach game has been done, and done well; I'm afraid a new game would turn out to be a pale shadow of that one.
The last succession game I participated in was a Sheaim one where we could only build warriors and had to use gate units to take over the AIs; that was fun. Similar concepts could involve Bannor with Demagogs, Elohim with Monks and Devouts, or anybody with Mercenaries or Werewolves.