Though it is very unlikely anyone will die or become incapacitated, the lack of evidence is not good.

A person whose score was still high may have moved into my property at the beginning of a separation in marriage and a score that was about to plummet.Furthermore, I've rented what I think may be termed a "C" class property to tenants who surely had super low scores but I had no problem with the tenants paying.Although I don't have any hard evidence that credit reports and background checks are helpful, I would still recommend that you pay the cost and run them if you're in any doubt. 

I would request the Seller have the entire property inspected and treated by an agreed-upon pest control company at their expense and that they provide you evidence of completion.Pests need food and water sources.