4. A plane on a conveyor belt, not moving with respect to the ground, will have no airflow over the wing and won't fly.
While this is true it is also correct as others have pointed out that the wheels are free spinning are are not drive wheels.
So it while the frictional forces on the wheels on the conveyor should counteract the initial thrust one can expect the thrust to allow forward motion with the wheels spinning faster than they would on a normal takeoff. Forward motion and airflow over the wings would then allow a take-off.