PacFlyer,
The short answer is, Dude, you failed your oral.
The APU on the classic, or, well, the newest 747 is a great big heavy thing back on the tail that may allow you to power and deliver bleed air to the aircraft on the ground.
It MAY even do that in flight.
It does NOT give you 600 pounds of thrust. Maybe some believe that, but I wouldn't count on it in a crunch.
Seriously, if it's that bad, the APU ain't gonna help, you are NOT gonna zoom over that hill with the goat on top by starting the APU.
You've already been corrected on the flaps, so I ain't going there.
Back to school Kiddo.......
PB