I have something to add about Riomaggiore:
We stayed in Riomaggiore. We loved the rocky swimming there. We come from Boston, USA, so the warm, clean water was something new to us! We stayed in an apartment recommended in Rick Steve’s book: Michielini Anna. We dealt with her English-speaking daughter Daniela (she was very nice; left us a bottle of her father’s wine as a wedding gift). The price was L200,000 per night for two bedrooms with double beds, an extra twin bed in a large hallway, decent bathroom and a good sized kitchen with small TV and a couch. We only stayed there because we could get a reservation there, and I didn’t want to worry about not getting a room when we got there (that didn’t seem to be a problem). It would be a very good value for a family or a group to stay here. The apartment we stayed in was directly across the street from Bar Centrale, which was very loud at night.