What if we took our small sum we have made and go to the town jail/dungeon. We get a sweet dose of suffering and we can find some desperate mortals. I'm sure we could convince someone to have their life indebted to us if we got them out of prison, we could probably manage to pay their bail, depending on who the violator is.
IRL prison was place where people waited while judge decided their punishment, not punishment itself (unless you were valuable noble). It's more likely that we could pay someones dues and indebth them, but I'm not sure if that's as usefull as you think it is... it all depends how binding their debth to us is.
Before or after that I say we look into the matter of the relative and his wife. She sounds like another person to possibly kidnap, but that would prove... difficult, at least.
Another? Why not the first one? We kidnap her and that relative guy will spend time trying to find her and will that way stay in town, we give our ghost his test subject and can feed on her suffering as well. It all depends on what kind of powers priests can use in this setting, or if he can contact competent mage to scry her location.
An what would be bad about a little suffering from bad slaves?
Also what do we need the rope for?
For the priestess-to-be-prisoner.
There's also tons of misery , hatred and self loathing in there, not to mention some twisted people making money out of it... in other words, people our former demon has dealt with before. But someone who spends time in brothel without spending time (read:
money) with the girls will be considered freak and attract unwanted attention from whatever passes for bouncer there.