Get another opinion from a proper specialist that doesn't do any repairs. A lot of issues can be fixed, or reduced to manageable levels (there will always be moisture in a house), by repairing gutters, clearing vents, removing soil against walls, fixing leaks and opening windows, etc.
Funnily enough, a company that makes money from doing all the things you've listed will say all the things you've listed will need doing!
A buyers' survey on our last house picked up damp 'issues'. We got a specialist in who quickly dismissed all of them and the reduction in price they were asking for too!
We're a family of five and always have washing on the go. We manage it by opening windows and using a couple of dehumidifiers.