Well, I guess you could say that Aria might as well do something if she's going to be at the village, so she could be a bartender and help out Almond as well. Honestly, I was thinking the same thing about the entertainers; one would think they'd all be in the city..o.o Anyway, I would assume they'd be NPC's, you don't do much as Priest >:
Or maybe the NPCs could be the same NPCs that were in Harvest Moon 64! That's a good solution to that, I think.
As far as Aria's relationships go, she's not really friendly with anyone; not even her stepsister because she's so introverted. She'll be either at the beach or in the pavillion writing or helping her sister do odds and ends. She'll be interested in anyone who likes literature though (b'-')b