Not pilot but:
1. The Moon-Earth's two-body system center is below the surface of the Earth (I don't argue the tides explanation, but the barycenter is below the surface of the earth)
2. A force can do various things to objects, not only
accelerate them. It can deform them. Your passenger door in differential pressure is deformed. You are probably thinking of kinematics and dynamics of
rigid bodies which is excellent for the initial question.
Your wing flexes
up during level flight even though there is no force unbalance, lift deforms your wing.
When I was in high school, 'force' was defined as 'the reason to alter the motion or shape of a body' (dodgy translation, but you get what I mean!).
When a train passes over a coin, the coins turns to foil. No (rigid body) acceleration involved.
Cheers!!
