That is rude. In China, pointing chopsticks at someone is a big no-no. And never stick your chopsticks in rice and leave them like that - it is considered an offering for the dead.
The pizza that you have been served has all the cheese it needs - asking for more is not a good idea. It will be offered to you if its needed!
In Korea, you should not even pick up your chopsticks unless the oldest person at the table picks up his or hers. The oldest person at the tables must eat first and then only, you should start eating.
When attending a traditional event in Georgia like weddings, it is respectable to chug the whole glass as opposed to sipping.
A person can only order cappuccino before noon in Italy, and when the latter is done it is considered a major violation of Italian Food Rule.