I would like quests that bring about or unlock/release TiTans, I feel that this is a way to bring some real chaos/fun/danger/excitement to the mid-late game. 

We could have anything from demons that go from faction to faction trying to recruit someone capable of helping them clear an ancient portal/ritual spot of theirs that's being held captive by some sorry do-gooders/guardian's', if you accept then you recieve a +1? to diplomacy with Titans faction & a -1 to all others.  If you accept or decline then the demons go to the next faction until the've recruited as many factions into there quest as they can, the faction that completes the quest recieves a special item of some sort and an additional +2? to diplomacy with Titans faction

to all factions would receive a message from a neighboring continents emissary sent by their TiTan ruler offering you the chance to show your fealty by sending him 50% of your current coin holdings or be marked as an enemy when he comes with his army (will spawn along one of the 4 sides the map, factions that show fealty have a +2? to diplomacy with Titans faction), the more factions that send him money the stronger his army is accourding to the amount sent

I think the interest for any mods is just low because we're still in early development of the game. Hopefully it will change later on.

What's missing from it? And yes.

All that is possible except the plague spell. I would also recommend the plaguestalker just being unlocked from a tech instead of requiring a building so the Ai can build it properly. I don't see the point of 3x damage for throwing knives in current version, would be interesting if it scaled with caster troopcount.

A mysterious being grants you a powerful item at the beginning of the game, on the condition that, at some unspecified point in the future you perform whatever it asks you to. This could be an unspeakable atrocity, a war against an ally, the sacrifice of your most powerful champion etc: the condition would be randomised and unknown to the player until the time came. Compliance would either be forced by the game, or noncompliance would cause the being to bestow a powerful curse on your empire.

A drunk wants you to kill a thousand beetles....!

Sincerely
~ Kongdej