Thank God 2/3 UHV criteria are by...i.e. it's possible to avoid the stupid Mongols.
Kutlag-Timur and Spiral Minaret were important. Roads to Herat and Marv need to be repaired ASAP.
Culture dial was always up (at least 10-20%). Most important tech is cheque system (to allow gold building, because with plenty of cities, it'll be close to impossible to maintain positive gold flow without it).
Switched to Shia since my cities kept getting Shia spread to them.
Buyids cannot be vassalized--they had conquered the Abbasids, but after I cleared out Persia they collapsed, and Abbasids respawned.
Khwarezmids declared war on me, so I vassalized them. Was going to keep their cities and liberate them back, but they collapsed.
Then got Abbasids as forced vassals. (How come I'm not the Protector of the Faith since I vassalized the Abbasids? I didn't dare capture Baghdad since they'll collapse)
In this turn I just got both the culture criteria and the land, after being crowned Shahanshah and trying to get the Zengids to see reason.
Damnit--the next turn, Abbasids collapsed. Zengids won't vassalize down to the last archer. Then I declared on PoA, and they collapsed. Finally got KoJ and Armenia to vassalize, and had to give them back their cities as well as plenty of resources to just make them unstable (instead of collapsing). I actually built the Tomb of Khalid ibn al-Walid which probably saved my ass (otherwise they probably won't vassalize).
Saving 2 great people and getting a second golden age saved me from collapsing till the end.