Dancing Hoskuld
Deity
I am testing as we speak, I will write down things I notice as I go along.
Firstly, The Tower Of Silence button shows up with that wierd border. This is my fault, I will see if I can't fix it, but I unfortunately do not know why it is doing that. I applied the same alpha channel to that one as I did the other buttons, and the rest seem to be showing up fine.
Behistun Inscription is lacking the -50% civic upkeep reduction, as well as the decrease to national rebelliousness. I assume that these could not be coded in? Also, the +1 happiness per city isn't working, it's granting +3 happiness to the city it was built in, but no others.
I don't understand what you mean by -50% civic upkeep reduction which is why it is not implemented.
I can find a tag for local rebellious on the building but not national. I need to check the other files and suggest a new tag maybe.
I may have missed the +1

Pir-e Naraki is granting a health bonus per city rather than a health bonus per state religion buildings. As you mentioned this is not easy to do, then this seems like a fine alternative. Building is working just as intended.
Seti Pir seems to be working just fine as well.
Zoroastrianism still has Nimrud Palace, Hammurabi's Stele Of Laws and Ishtar Gate as religion wonders. I assume you didn't mess with that part of the code?
Did you copy all the code I gave you across? Changes to Nimrud Palace, Hammurabi's Stele Of Laws are in the Modules/DancingHoskuld/Custom_Religions/Std_RoM_Religions and changes to Ishtar gate are in Modules/Tsentom1/Ishtar.