" ... the listing agent isn't going to let you climb on the roof, go into crawlspaces/attic ..." I have done all of those things on home viewings / open houses

" ... the listing agent isn't going to let you climb on the roof, go into crawlspaces/attic ..." I have done all of those things on home viewings / open houses. I've opened septic risers, started generators, tripped breakers ... Nervous smiles were the worst responses I've ever gotten. You, and your sibling poster, are correct though: a real, comprehensive inspection is hours long and no amount of brashness is going to bridge that gap - but there is a LOT you can do with 30 minutes of knowledgeable poking and prying. You don't need an hour to see if the sills are rotting or if there are no foundation anchors ... or if all the floor joists are swiss-cheesed up by 40 years of ad-hoc electrical and plumbing runs ...