Good luck MrsP.
Sorry to hear about everyone else's frustrations.
I've been staying away because our purchase has been so frustrating I could cry. The searches came back and the new pluvial flooding search came back as a problem. Some nonsense about up to 1m of surface water risk (but the house next door has no risk, apparently, despite it being impossible for one house to be flooded to a depth of 1m and not the other as the ground is pretty much flat) So we had to pay for another search, which had a very different result. I checked and getting insurance doesn't appear to be a problem. DH did find it a problem, but I think he told the companies there was a risk of flooding, whereas I used compare the market who just asked if it had ever flooded (no. Not even during that really heavy rainfall that flooded everywhere in Newcastle, which was definitely a more unusual event than the alleged risk attached to this house) and got loads of quotes, most of which were totally reasonable.
DH knows a hydrological modeller so he phoned him and he looked though tonnes of data, including weird remote sensing stuff we'd never have gotten hold of and information about the drains and things. Anyway, he said that unlike river and sea flooding models, the pluvial (surface water, or big puddles as it actually is) models are currently crap to put it mildly. It's all very proprietary and the models are full of assumptions. They're also at a resolution that makes the data useless (because of the micro-scale aspect of puddles).
He doesn't think there'll be a problem at all. The only issue may be around future insurance costs depending on what the insurance industry does with the new models. But the models themselves are really terrible. Sigh. He said even if there was a bit of a big puddle, it's easy and cheap to put the kind of measures that would stop it coming near the house in place.
I think we're still going ahead. We'd have to go into rented otherwise (which I don't want to do) and I really don't think it'll. Our hydrologist friend said that it's like those surveyor reports that tell you that there's a tree in the garden. Sure it might fall down, but the risk is really low. DH is going to try to negotiate money off the agreed price due to the totally unexpected risks. I've warned him that they may well say no because the valuation survey came in fine. But, equally, any other buyer is going to get the same searches we have and see the same issues (or pull out entirely) so they might be more willing.
I took the children up to see the house tonight. DS2 has seen it before but DS1 hadn't. They both really like it. It is a very nice house, and even bigger than I remembered. The flooring isn't as bad as I remembered either (still not what I'd choose, but something I can live with for a while).