Can an African who has a bachelor's degree and a TEFL certificate with fluent English be allowed to teach English in China and how can they make it?

Answer 1

Yes, absolutely.

When I was living in China, I knew multiple Africans who were English teachers, and I knew of many more (though I didn't personally know them). They had varying levels of English fluency, but they were all teaching English in some capacity (in a classroom or one-on-one). In China papers and certifications carry much more weight than capability. If you have the credentials, you can definitely find an English teaching job even if your English is not perfect.