remember to delete the forces when is disabled.
fix arrow scaling.

little detail that messed up the arrows in some situations.
don't search for the CoM in every Update.

keep the reference instead so is faster.
looks like we don't need everything to be public
this should be Vector3.zero actually
refactor
instead of using a scale, limit the maximum length of the arrows.
use get set for VectorGraphic.color
add Rotation mode, so besides translation you can balance rotation.
use LateUpdate instead of Update

This way arrows stay still while you drag stuff around.