I am presuming that anyone represented in the shop can give points. But what does it take to get the blasted points? I've done Saggi, Pete, Maleria, and Cursed, and not one point. Do you have to do all and not quit any, or what? Is there some trick I'm missing?

You get them randomly, I think. Sometimes they can be stingy, and other times you can get a lot. Hopefully your luck improves!