This is a restaurant - some of us here understand English. Therefore, quite apart from the racket you're making, do you really want complete strangers to hear about Auntie Ginnie's hernia operation, what a low opinion you have of your own children and the details of a shady financial tranaction you're planning? There is no need to shout at the waiter - if he understands English, then speaking slowly and clearly at a reasonable volume should suffice; if he doesn't, then shouting is not going to do you any good at all. Pretending you're having a birthday party does not mean that you will be brought free desserts - singing 'Happy Birthday' repeatedly when it's not anyone's birthday is not going to improve my opinion of you. The bill brought to you is not in dollars, okay? What on earth would make you think that a tiny neighbourhood pizzeria would bill you in dollars? I think it's really cute that you've learned a little Italian. Walking up to other people's table and saying 'Mangia, mangia!' is less so. Normal people take their photographs at the table or outside the restaurant - why is it taking you 10 minutes to noisily leave the restaurant and why are you taking all those photos outside the restroom?Cordially yours,
PS I've met enough civilized Americans to know that you're not the norm - Deo gratias!