Check the roof - what kind of condition is it in. Ask to see the awnings out. Are they good. Can it be put in and out , any problem. Power awnings should be tested also. Open cabinets and cupboards. Is there any sign of water damage there. We also asked to have water connected and sprayed the roof down watching for any interior leak - we used the pump, flushed the toilet, ran water in the sinks and shower and checked for any signs of a plumbing leak, turned on the furnace, then the A/C. Asked for the refrigerator to be cold and turned on the kitchen stove. Used the microwave to heat a cup of coffee. Put slides in and out. As we were new to rv's, this also helped us learn a little about how things operated.