I agree on most of your points except that :

• genocide has nothing to do with communism.
• China is no longer communist. At all. You got your private property, private economy and the list goes on.

While I agree that a 'pure' Marxism application leads to dictatorship, it's still an interesting ideology responsible for most of social progress in Western Europe for example (look up what role commies had in liberated France and what laws they put into place : we're talking health care, paid leave, etc...)

China's a technocratic dictatorship, if you have read Marx, you KNOW he's rolling in his grave thinking about how China twisted his works.