Vampires will not enter a temple that has a priest in residence.

Priests tending an altar should repair the walls and doors of their temples if they are damaged, like shopkeepers do. (In NetHack 3.7, peaceful monsters avoid digging temple walls, but the temple can still be damaged by other monsters or the player.)

Pets should not attack coaligned priests.

When you convert a cross-aligned temple’s altar, there is a Cha/100 chance that you also convert the priest along with it, and they become coaligned rather than angry.

Non-coaligned priests require more money in donations than coaligned priests do to get the same benefits.

You can buy indulgences from coaligned priests, which will remove or reduce god anger or negative alignment.

Track not buying protection from a priest as a conduct, as a weaker version of atheist.

Minetown shopkeepers should be gnomes, and the priest and Watch should be dwarves, either by creating new racial variants of those monsters or via a monster race implementation. It doesn’t make any sense that everything in the town is run by humans.

Revamp the Oracle: move it lower in the dungeon, add level variants that make it look like a real temple instead of a small room inside a big room, and make the Oracle act as a real priestess, providing consultations along with regular priest services.

Aligned priests in a coaligned temple attempt to pick up corpses lying around and sacrifice them.

Priests attending a temple altar can magically fix their temple’s walls periodically like shopkeepers can.

If Astral denizens are able to steal the Amulet from you and try to ascend with it: Keep track of the god of the current amulet-bearer (whether you or someone else). Priests and angels aligned to that god grudge all others, and all others grudge them.

Gods should react in some way when the corpse of one of their own priests is sacrificed. They currently don’t (unless it’s a same-race sacrifice) and this is weird.

Donating more than 100 gold to a priest but still less than the required threshold to actually get anything causes the priest to say something gracious, rather than “Cheapskate”.

Slightly bias priests’ and angels’ allegiances on Astral to be generated near their high altar so that the player can get a clue, but not enough so that it’s obviously distinguishable from random noise.

The more gold you pay to a priest, the stronger his god becomes. Newly generated priests of that god could get better equipment, or altars of that god might be harder to convert. In Moloch’s case, Gehennom gets slightly harder if you pour a lot of gold into his temple. This applies with money donated to your own god as well, but the effects are naturally less visible since you won’t go around fighting your own priests or converting your own altars.

Temple priests can sell holy water as a donation benefit.

A YAFM when you donate exactly 1/10 of your gold to a priest: “You pay your tithe.”

If a priest gives you two bits for an ale while hallucinating, change the message to “two bitcoins for an ale” (or just use a hallucinatory currency.)

Replace all the priests of Moloch on the Astral Plane with (still hostile) priests of the other gods. Moloch is a disgraced, hated god, and his priests have no business there.

Permanent alignment conversion prevents you from receiving any more protection by donating to a priest ever again.

One Gehennom “special room” should be an active temple with a peaceful priest of Moloch.

Corpses dropped by aligned priests or priest player monsters are always blessed.

Aligned priests can sometimes generate with 1-2 holy water instead of 1-2 of their spellbooks. Moloch priests will get unholy water rather than holy.

Priests object to you locking the door of their temple, and will unlock it if you try. If they cannot for some reason, they get angry.

Wandering hostile priests of Moloch occasionally generate in Gehennom.

Additional clerical spells for aligned priests to cast: raise undead, floor to lava, ball lightning (not a ray and thus not reflectable), summon elemental.

Color priests differently to distinguish them from player monsters.

After a priest gives you two bits for an ale a certain number of times, they say “wow maybe I should not enable your alcohol addiction” and stop giving you more.

If you manage to get an aligned priest to wear a helm of opposite alignment, he becomes a priest of a different god. (Not defined what this should do to Moloch priests; maybe their heads explode?)

It costs more money to donate to crossaligned priests for protection.

Peaceful priests and angels of your own god on Astral help you out by attacking hostiles. Possibly only if your alignment is good.

Player monsters, crossaligned priests, and hostile angels on the Astral Plane are able to steal the Amulet from you. Should they get it, they will try to make a beeline to their high altar to sacrifice it. The player is also able to steal the Amulet back, though; and wearing the Amulet acts as one turn of protection against it being stolen; an attempt to steal it will just remove it from your neck. If something else ascends, your game ends in an escape. However, all these monsters are hostile towards the Amulet-bearer, not you; so if it gets stolen from you, the pressure will let up a bit.