Anybody see the P-39 Aircobra? Same idea, which would work if you find a shaft light enough and strong. Many of the nitro boats use speedometer cable which, when dries out from lack of oil, comes apart and siezes. Cooling may not be a problem if you have airducts to the engine like in a deducted fan. Maybe have a heatsink head.
Weight is my concern since there will be many more parts, such as a coupler head for the spinner and prop, the shaft and shaft tube, and then a cooling system such as added ductwork and possible heatsinks. But overall you may have a well balanced plane with more scale appearance.