What are the basic principles of Confucian philosophy? How did the formulation of the principles constitute a response to China’s disarray at the time? Why do you think Confucianism, rather than Legalism or Daoism (Taoism), eventually became the philosophical basis of the Chinese empire?

China was in a state of what Wright refers to as "chaos and moral decline" during the Eastern Zhou (Wright 20). Confucius's two main principles of li, or correct ritual, and ren, or "humanness," brought order to the chaos by stressing the importance of carrying out certain actions but also carrying them out with the proper degree of humanity. Without this sense of ren, Confucius thought the practice of rituals would be hollow. By following correct actions with the correct approach, order could be brought to a disorderly society. 
Taoism, which allowed for greater freedom than Confucianism, stressed following the tao, loosely translated as "the way." However, this philosophy was not as powerful as Confucianism as a philosophical basis for China because leaders often lost their sense of the tao if their empires became too advanced. Taoism works best in a simple, peaceful society, and is not always amenable to the demands of a quickly evolving civilization, which China's was at this point. Confucianism and Taoism were often practiced simultaneously, as people used Confucian ideas to guide their public lives and Taoist ideas to guide their private lives.
Legalism, which instituted a system of rewards and punishments, did not necessarily create moral leaders. Only Confucianism, with its emphasis on li and ren, was able to create the type of moral leadership that could create an orderly society. That is why Confucianism became the philosophical basis for Chinese life.