I'm not denying that China has shortcomings. I believe you are magnifying them beyond their actual levels.
As for Cheng Enfu's diagram, it essentially describes increasing planning and decreasing marketization over time. Marketization helps socialize production, and over time this is reigned in, creating a fully planned economy.
As for Mao Zedong Thought, some aspects have applicability elsewhere. The Mass Line is a generally useful tactic, Protracted People's War can be useful in largely agrarian countries with high peasant populations and smaller urban centers, and so forth. It isn't universal, but Mao Zedong Thought works well for China and tactics from it have seen success in the global south, including in Vietnam.
As for your insinuation that there are privledged people in China, yes, this is true. This is a side-effect of the socialist market economy. It's a tradeoff, an inefficiency that serves as a sort of price for the positive aspects of the socialist market economy. Excessive luxury is being cracked down on, and as China's socialist system develops, obscene wealth is being diminished while absolute wealth rises for the average worker.