At which point in a conductor do charges flow?
Charges flow through the topmost layer of the conductor.
Charges flow through the topmost layer or the skin of the conductor due it being the path of least resistance. This is known as the 'skin effect'. The reason for the effect is that, when the charges move, they repel other charges and try to be as far away from each other as possible. The farthest point is always the surface points.