OTB blitz chess conventions

I'm of the type of chess players who learned to play on the LCD screen, so when I played in this for-fun-only blitz tournament at school, I didn't know the most basic thing, such as you only push the timer with the hand you used to make the move (I kept one hand on the timer for a few moves :). I was quickly informed and corrected that mistake.

Later, something else happened however, I was playing this game where I was short on time (~20s at 1s increment). I made a discovered check without annoucing it (I don't think this is a problem) and my opponent didn't even see it and made an illegal move. I got excited and claimed the win before he even got to push the timer. He was a good sport and conceded defeat without objection but this got me thinking, do professional blitz tournaments use touch-move rule? If not, could he could have legally changed his move? (since it was still his time ticking on the clock)

This led to other questions:

1) How do you claim repetiton and 50-move draws in blitz?

2) In classical time control tournaments, do you have to record moves on the scoring sheet? What if you are short on time trying to reach the 40th move?

3) If you are promoting a pawn in blitz and the piece you want is not available to be put back on the board what happens?

Apparently same questions were raised before:

http://www.chess.com/forum/view/general/otb-blitz-touch-moves-amp-illeagal-moves

well that at least answered my original question.