As an investor I've paid way less for getting a house sprayed.

One thing to consider... the exterior walls may not be insulated but this can be fixed with spray foam. 

My current pre licensing teacher told us that we (females) should take a self-defense class, carry pepper spray in our purses, when showing a house ALWAYS walk behind the individuals looking inside of the house, never allow individuals to get inside of your car, always meet individual at the office or a place where you feel comfortable.

I'm negotiating a 3unit all 3 bedrooms built in 1840 and needs a lot of work and just had a skunk get in and sprayed in one of the units. 

These cabinets become damage after a water leak occurs and the tenant doesn't say anything until months after the leak.The Fix:I spray flex seal (rubber in a spray can) inside every cabinet with a water line inside; this will protect particle board "wood" base from negligent tenants. 

It took a lot of turning the water off to fix one leak, then turning the water back on to discover the next one was spraying.  

do you spray or roll?

If there has been rain lately and the ceiling is not wet, then it's probably an old leak and I would spray the ceiling KILZ on it and see if it reappears the next time it rains.  

It was evident that he understood because there were 15 gallons of kilz sitting on the job site.Instead of Kilz-ing the house as discussed, the workers just sprayed the ceilings with latex ceiling paint.

Also I heard that spraying insulation may help but only slightly, I'd prefer to do it the right way once.