Ear plugs...
You seemingly have the desire and tenacity for your project, but my quick response is 'wince'. But curious.
To answer the question about forcing the heat into the basement, our AF (and others no doubt) use nothing more than a small fan that circulates a fraction of the room air. The propane heater is extremely quiet and we leave it on all year. The heat from it helps also. Long term zero temps are clearly a different story, but we've had no problem being in the teens for a few days, or below freezing avg temps for week plus.
