I’ve had these issues too.
The plumber found the stop cock (although I have no idea were it was, sorry).
On the insurance I had the same issue. However, they only needed to know about the roof for building insurance, insurers don’t ask this if you only take out contents insurance. As we are covered from a building insurance side from the charges in the community fees I think we only need to take out contents insurance. In which case you shouldn’t get ask the roof question I think.