[sourdough]

For the "heating system" there shouldn't be any damage if you clean those heating ducts. As far as the flooring, it would depend on how much water and how long it sat and how well you cleaned it up.

Leaving the gray water valve open.....sort of a toss up for some. Nearly everyone I know leaves them closed. Open when it's time to dump. Between slinky buildups, sewer gnats etc. there is no good reason IMO to leave them open...btdt - unless running the washer.

Remedy IMO is either educate the "folks" on closing faucets etc. and RV usage or curtailing the wayward cat.