Burnsaber, I like your idea on Holy War Lite
If I could add just one more idea for you to ponder:
Make all *national* pure priests (so not those mage-priests or SC chassis "priests") gain one level in Holy. So H1 priests would become H2, H2 would become H3, and H3 would become H4 (and in cases where H3 priests can be recruited everywhere (like the Lizard King for C'tis) change them to Capital only). Of course the price would have to be adjusted accordingly
Currently there is really no incentive to buy national priests (except H3 ones, if you have a good bless the possibility to bless them all in one go and then smite smite smite), as indy priests are able to do everything national priests and you can recruit them from non-fort temples.
For Holy sites, maybe monasteries from where you can recruit special priests or sacred troops. Like a warrior-monastery, from where you can recruit crusaders (Heavy cavalry stats but they are sacred), Faith Healers (immovable H2 priests (movement 0/8 for example) who have the Healer attribute; those with afflictions would have to come to them to get a chance on getting healed), a location where you can summon Flagellants ("Temple of Retribution" -> A priest can enter to summon flagellants, and perhaps even a place where you could recruit sacred assassins ("The Lord works in many ways", recruit assasins who are considered to wear the Shroud of the Battle Saint).