Tony Cox wrote:
1) Hot air balloons use about 15 gals of propane/hour,
which isn't vastly different from my 182 burn.

Yes, but isn't that 15 gals of a gas volume (ie less density).
In terms of lbs/hr of fuel burned it should work out at a lot less. I
would imagine that baloons are a hell of a lot more efficient than
aircraft in terms of endurance but when you start counting in range
efficiency...