I'm about to buy a house, and I got the RICS Homebuyer Report sent to me
today.

That sounds better than any report I've ever seen (although that's not
many). You do need to check the rotten timber though. In particular, these
things can get out of hand if someone has been overzealous in installing
insulation and hasn't allowed ventilation of the roof timbers. In the worst
case, all the rafters may be rotting.

The damp part of the report is as close as they ever come to saying it is as
dry as a bone.

Christian.