I have pieced together some things to get a working Patriarch, here is what I have.
In export_descr_character_traits.txt, I added a third level for "Trait PriestLevel"
Level Patriarch
Description Patriarch_desc
EffectsDescription Patriarch_effects_desc
GainMessage Patriarch_gain_desc
Threshold 3
Effect Piety 2
Effect Level 3
Effect HeresyImmunity 1
and a trigger
;------------------------------------------
Trigger priest_patriarch_o
WhenToTest CharacterTurnEnd
Condition AgentType = priest
and Attribute Piety > 5
and I_EventCounter Patriarch = 0
and Trait PriestLevel = 0
and FactionReligion orthodox
Affects PriestLevel 3 Chance 100
In descr_character.txt I added a fourth model for each Orthodox faction
In the expanded.txt/text folder I added the following to Orthodox religions
In the export_vnvs.txt/text folder I added-
{Patriarch}Patriarch
{Patriarch_desc}This man has become the patriarch of the Orthodox church.
{Patriarch_effects_desc}+3 Piety
{Patriarch_gain_desc}This priest has been elevated to the title of Patriarch within your church. May he be a true spiritual guide to you and your people.
For the campaign_script.txt I used this-
I can tell you that it works, I recently added this to my own mod and started a new campaign. By turn 30 the Russians had the Patriarch.
As for your 2nd question I'm not sure as to what you are asking. Did you make a building in each of these towns and want a Patriarch spawned due to someone controlling the town? Need more information please.
VB