Great piece. You seem to have written it? If so, good job.
What does homotonic mean? It's used without being defined in the sentence:
> Chinese has many words that are both homophonic and homotonic.
From context, it seems like its being used as a synonym for heterographic, but the word seems like it means "same tone". That sounds like it means words which are homophonic and where the speaker uses the same tone when saying them, but I doubt it.
I believe homotonic refers to the intonation when pronouncing the character (there are 4 intonations in Chinese, with a fifth "blank" tone). In this case, it is referring to words that are pronounced with the same sound, in the same intonation.