Capitalizing Priest and Priestess in a fantasy novel

I'm copyediting a fantasy novel. Two major supporting characters in it are a priest and priestess. I'm struggling to decide when to capitalize the words. My eyes are beginning to blur at the sight of the words "priest" and "priestess". Capitalizing them all the time makes the novel look like an 18th century tract.

There is also a profession called Singer; the capitalization is important to the author. So some sentences look like

"He left Priest and Priestess and returned to the Singer’s bench."

Can anyone assist? I'm sort of thinking:

No:

"the village priest"

"the souls of the dead priests and priestesses"

"priests and priestesses"

"even priests had to live with the separation between their souls and the All"

"the priestess"

"your priest"


Yes:

"Greetings, Priestess."

"Priest and Priestess walked into the room"

I'm thinking I may have to do that with Singer as well, and probably also Soldier. In the book they're roles with ritual importance -- also there is a god called Soldier. But so far I think I will not capitalize unless they're proper nouns. Otherwise it gets a little blurry to read.