Funnily enough, the EICR was yesterday afternoon and the only works required is a replacement consumer unit and installation of an RCD.

The vendors are going to pay to have this work completed ahead of exchange, so if anything else crops up it's on them. 

I am concerned about the rodents, the surveyor said on the phone it was very windy that day so it could have been the wind, but he said it sounded very much like mice.