Here's a little something to do if you're bored......

More in the "Guardian" here :-

http://www.guardian.co.uk/football/2012/may/31/you-are-the-ref#_

As an ex ref (small stuff - inter-university and the like) I cannot recall any specific rules in these areas, so I would say all 3 are up to the ref. He's entitled to blow the whistle again to cancel the start of a game but would not do so if the goalie had injured himself after he'd blown up for the start; mocking can be regarded as unsportsmanlike (but I doubt any ref would give it unless the player had previously been warned); a ref can change his mind on the award of a foul using any evidence that he gets before signalling the kick can be taken (but most wouldn't do it, other than for a ref's assistant intervention).

Probably shows I should not have been allowed on a football pitch!