Making the "stop" sign with your hands in Greece is extremely offensive
True. In Greece, any signal that involves showing your open palm is extremely offensive.
Chewing gum is a habit considered fancy in Switzerland
False. In Switzerland, France and Luxembourg this is considered vulgar. In Singapore, it's illegal!
Never toast with beer if you're in Hungary.
True - Hungarians may interpret that as the worst discourtesy.
In Russia, you shouldn't be mixing the vodka with anything else.
True.
Shaking hands in the Philippines is seen as agressive
True.
In Egypt, there is a specific protocol to serving drinks
True. You cannot refill your own glass. You have to wait someone else to do that for you.
Slurping noodles in Japan is a way to show you're enjoying it
True.