The problem with star based rating systems is that they're INCREDIBLY subjective. I oftentimes read yelp reviews that are 3 star reviews where the person raves about the restaurant and then complains about a minor issue. I have a similar issue with app store ratings where I've had a rash of people rate one of my apps 1 star with the review text reading "I just downloaded this, I'll raise my review to 5 stars if love this app".
It's how the "official" reviews from Marriott/Hilton/etc all work
2. Ask each person a different objective question, intentionally filling in the gaps.
3. After a few people, you have an objective, relatively thorough view of the house, but you've not burdened any of your users with more than one question per stay.