The rise of China and the economic development accompanying China's rise is peaceful for the world for several reasons. First of all, China's economic growth will spur development of economies in developing Asian nations. The more developed an economy, the less likely its rulers or citizens are likely to resort to violence.
China has always been big brother to it's own citizens. The country also doesn't understand how to deal with North Korea, so any more power and the world is getting nervous. It's policies are too strict for it's citizens to even be considered a good world power. And when it defends North Korea when North Korea is a scary place with brainwashed citizens, I can't see that ending peacefully.