Zero. They don't exist.
TRICK QUESTION. THEY CAN'T CHANGE ANYTHING**
None. They can't climb the ladder.
Two. One to hold the bulb, and one to drink until the room starts spinning.
Make that change"
Gingerly.
Because they can't compete with an invisible power that actually exists
Because people are offended by seeing Boo Bees.
That's when the ghosts do their spring screaming!