No, karate is from Okinawa. It does have roots in China and was created by blending the Okinawa Tegumi wrestling with White Crane Kung Fu.
Yes. It is probably the most practiced Martial Art in one form or another.
yes, it's very effective and healthy for your body
Chinese martial arts, as with all fighting styles have been around since pre-history; unarmed combat has been practiced by every culture, and by every people, however, what is unique about China is...
well lets see. theres northern style, gung fu, win chung, jeet kune do, and more. i cant name all of them.