Our host met us at the ferry stop and explained everything well. She accommodate us with an earlier check-in for an extra 20 euros. The boat stop was indeed a short walk to the condo. The location and the actual apartment was fantastic. There's no elevator so anyone with a disability or elderly might have trouble with the narrow stairs.
My only comment would be the third bedroom is not a real stand alone bedroom. The owners converted an empty hall space and put curtains over the entrance area as the door. You have to pass this "bedroom" before you can get to another bedroom. This was not a problem for us since we're a family that didn't need the additional privacy or a locked door. But I can see some guests being surprised if they were going with couples or groups of friends.
I would definitely recommend this Airbnb property to anyone visiting Venice.