only if no ones there to see it (a doppleganger is not a ghost its just someone who looks excactly like another person, but not related)
it makes things move without friction
It either means you move them without knowing or you have ghosts in the house that move them.
You can
Telekinesis.
Flexibility is being able to move your arms and legs without pain or tightness.
Lions can move. It'd be quite difficult for a meat-eating, predatory animal to survive without being able to move.
Breathe, Eat/Drink, Move, Reproduce
According to Bernoulli's laws of motion no
Not if you are under 18.
Not without your parents permission.
uses many air masses to move things
of course of course