If I charge for house sitting, so over night stays, does this include drop in visits/ potty breaks during the day? Or, do I charge for drop in visits and potty breaks during the day additional to the over night charge?
Up to you, but my overnight fee is 24 hour all-inclusive (so includes all walks, feedings, etc..)
The service is called "house sitting," which is no different than boarding, except that you are staying at the client's home. It should be viewed as a premium-type service (which I see your fee does reflect) because you have to uproot yourself and move into someone else's home.
You should discuss with the client how much time you need to be in the house, especially if you have other drop-ins or walks booked. However, like boarding, the "nightly" fee should cover feeding, walks, general play time, etc. Because you are independent, you can charge however you'd like, but if it deviates from Rover's FAQ, then you should describe what you provide for each service so that clients know before they contact you.