Heh, my old-timey outlook may amaze some of you but...
Rule - This is commercial equipment. If it could hold up on route, there isn't anything that someone can do to it that will make it fall apart now.
My tilts are always tight, and I set my games so you can't restart them during the game, so I can't imagine anyone walking all over the house with a game. As for shaking, I used to always think it was cheating until a guy I was playing a pin with watched me get a SDTM drain and he said, "No man, you gotta shake it to save it!" and I said I didn't want to break it. He proceeded to violently move the game back and forth about a foot in both directions a few times (it was his machine) and he said, "Ain't gonna do nothing. That's what they are designed for."
He then had me play and shake the hell out of the machine until I tilted. He said that once you hit that tilt, you know you did it too much, and that is the rule. I've shook the hell out of my machines ever since