OP there are certainly indemnities that can be taken out, the correct way would be for the vendor to pay for them but many vendors just shrug and the purchaser ends up paying. You are correct tho, it won't pay for corrective works only legal costs and fines etc I think, tho they may vary. Having said that it is pretty unlikely anyway that the local authority would be concerned about it at this stage
TBH I would mainly be concerned that the electrics were safe: the rest a competent builder should be able to give an opinion of how good a job has been done by having a poke around. TBH the house sounds as if it will be in massively better shape than 99% of the houses in the UK so I would go for it if builders think its well built and the electrics are OKd by an electrician (even with electrics they can generally tell pretty quickly if there are major issues)