#1 - No keys, cell phones, or drinks on the glass.
#2 - No monkey flipping (that is, hitting the flippers continuously)
#3 - Play your entire game
#4 - If you have a question about gameplay, strategy, or rules, by all means ASK!
I don't have a problem with harder play on my games. They all have Tilts adjusted and that's why they're there. I've never had anyone pick one up and drop it which is where I'd draw the line of mishandling the pin.