I have a 1993 HR 1000 built on the Ford chassis. I have not had overheating issues even pulling a Jeep Cherokee in the mountains. I have also not noticed too much heat radiating from the dog house into the cab. HR placed a fair amount of insulation on the dog house. Most of the problems with plug wires melting can usually be traced to missing heat shields on the exhaust manifolds or exhaust leaks at the manifold. I just ordered the Banks power pack system since I have two broken manifold bolts with the accompanying exhaust leaks. I should be able to put them on at the end of this month.
On the smell you might try to rent an ozone machine. Open all cabinet doors and let it run for a few days. Then turn it off and open some windows give it another day or so before spending time inside. Those systems are used by restoration companies to remove smells from various places.