"Tipping" in America

Many foreign students are confused about "tipping" in America.  Basically, in restaurants, the waiters in America are paid very low wages and they rely on "tips" to make a living.  Indeed, some waiters and waitresses can make about $100 per day just on tips.  However, it all depends on how well business is on certain days/nights.

Here's a nice article and video about when you should and when you shouldn't tip.

http://shine.yahoo.com/financially-fit/common-tipping-mistakes-221500121.html

1)  Most countries do not have this "gratuity" or "tipping" system.  How do you feel about this system?

2)  Some restaurants add a tip to the bill if they see that you are a foreign customer.  What do you think of this practice?

3)  What if your waiter/waitress does not provide you with good service or if this person is rude to you?  The video suggests you should still tip, but then you should talk to the manager of the restaurant about the waiter/waitress.  What do you think of this policy?