I'm sorry to say I haven't got much about their practices or seats of power, other than what's in the book. In my campaign, they're pretty common and most villages have some kind of shrine or other place devoted to the everyday ceremony to please the god. The priests are quite altruistic, compared to the worshipers of Rust or Heme, and go about their daily lives trying to ease the harshness of everyday labor to their followers. They still lead quite wealthy lives compared to the common man, on account of the tithe and other donations, especially in times of need. I picture them occupied with performing endless small rituals, all of which is supposed to keep their God happy. Because they believe the God to be ever on the prowl for wrong doers, always searching for someone, a prey, to strike at without warning. Like a snake on the hunt. By performing these endless, small rituals they feel they can prove they are good and firm believers and thereby make the God ignore them, continuing his search for sinners and unbelievers elsewhere. Sometimes it seems to work, other... not so much.
The are viewed upon by the followers of Rust as described in the Gamemaster's guide (p.40)