Soccer 13/14 Law 16 - The Goal Kick - Stationary or not?

I came across an interesting discussion the other day about goal kicks. The discussion was specifically about whether the ball needed to be stationary at a goal kick. It was presented such that the Laws of the Game did not state that the ball needed to be stationary at goal kicks, but did for all other kicked restarts.

With a bold statement like that, it almost necessitates looking things up in the Laws of the Game book.

Soccer 2013/14 Law 12 - Hanging off the crossbar (Updated)

Something that was brought up after the prior Law 12 discussion was how FIFA's Laws of the Game apply to a situation where a player hangs off the crossbar during the course of play. This player could, of course, be a goalkeeper, a defender, or even an attacking player.

So... what do we do? My immediate instinct is to blow the whistle and stop play, but why? There's nothing outright in the Laws of the Game for either soccer or futsal that directly discusses a player using the crossbar as an aid to play.

So where does that leave us?