I have little kids come over when we have parties, they chimp flip and I have never felt the need to rebuild flippers because of it - if you do - there was probably something wrong with it in the first place. I also don't call them morons, they are just not educated....so I educate them.

With the exception of a few intentional asshats under the influence of alcohol, the rest is about expectations and guidance. These events are open to the general public, not exclusively pinball hobbyists. If you rub your game with a diaper it should probably not be there, if you are concerned with specific types of handling, you should be willing to supervise your games. I think it would be a unanimous conclusion that taking a hammer to someones games would be abuse, but a lot of folks don't consider lifting, sliding, shaking or hammering flipper buttons as abuse to a commercial pinball machine. If you do, you'll need to spell it out ahead of time at the location, or don't bother bringing your game.

That depends, did they notify me beforehand to take my shoes off, or are they already scolding me because I walked in with shoes on? ...If I hard nudged into a tilt and you gave me a dirty look, but you never told me your expectations, I'm going to tell you to chill out because the game can handle it.

One persons definition of overdoing might not be the same as another persons.

See Vids guide. Other than that, lock the coin door....sheesh.
https://pinside.com/pinball/forum/topic/replacing-the-beer-seal-vids-guide