As a house buyer myself I would always get a survey done by an engineer who will look into the attic to check chimneys and water tanks. Most solicitors would advise their clients to get a survey done. However a structural survey would not advise on planning permissions (it is up to the buyer to do that). As for the plumbing, well there are a lot of houses out there, some brand new, with dodgy plumbing. The chimney can't be that bad or it would have gone on fire already.
We all enter these situations when we buy houses, or second hand cars for that matter. There could well be a lot of faults with a lot of houses that people don't know about until they move in and find the soapy water from the sink is appearing up into the bath, or that the garden floods when it rains.
When I buy my next house I fully expect that some drains problem or other may present itself in due course, as might appear with any house. Your sense of responsibility is to be admired but not sure there is anything you can do. Unless you build it yourself every house comes with 'baggage' and it is up to the buyer to 'beware'.