touch move (sort of)

Say you are playing in a tournament and about to promote a pawn. No pieces are available, so you tell the TD you need a queen. The clocks are stopped, and when returns with your queen, you inform him you changed your mind, and would rather promote to a knight, or even make a completely different move.is this acceptable, or does it violate the touch move rule in some abstract way?

I don't know for sure, tricky question.

I'm guessing that you can probably change your mind, until the clocks are restarted.

Presumably you changed your mind because you thought it over, after your clock was stopped. So I'd say it is more egregious than a simple touch-move error and probably not kosher.

Until you physically take a piece and place it with your hand on the board, all that happens in the background is irrelevant. So, yes, it is acceptable. The time on the clock, however, should be recovered by the opponent if you change your mind.

I added a sentence regarding the time.

If a player stops the clock to obtain the arbiter's assistance, the arbiter decides if the player had a valid reason for stopping the clock.  If the arbiter decides that the player did not have a valid reason, he penalizes the player (the penalty is at the discretion of the arbiter).

Stopping the clock and changing your mind would probably result in a penalty.

Ok, what about the following scenarios:

Pieces are available, I pick up a queen, hover it over the board, then put it back and take a knight

Or

Push my pawn to the queening square say queen, and then place a knight on the board

Ok, what about the following scenarios:

Pieces are available, I pick up a queen, hover it over the board, then put it back and take a knight

Or

Push my pawn to the queening square say queen, and then place a knight on the board

From FIDE rules:

looks like woton cleared that up nicely.