My English isn't as good as a uni graduate's but I think that's the point. China is so big that if the country wanted to recruit purely professional teachers they could never satisfy the demand. As a result, plebs like me are employed as we may not be professional but there is no substitute for a native speakers intuition. Regardless of how good a Chinese person's English level may be.

Well, if you are a native speaker, you should equally as fluent as any university graduate.