The 'Chinese' Theory: For and Against

[Jorge_Stolfi]

However, these are not the most interesting candidates. For the theory to work, the area would have to be well reachable by land or by sea, and represent an 'area of interest' in some way or another.

Agreed.  But those criteria are broader than one may think.   "Reachable by land or by sea" only excludes jungle areas.  In the 1600s or thereabouts, a small obscure island in Indonesia became "an area of very high interest" because it was the only source of nutmeg. 

Anyway, the tones remain a problem, not for the native speakers of course, but for the foreigners. People who have not learned to use them from infancy need considerable time to 'restore' the capability of properly using them.

Indeed!  I know in theory what the four tones of Mandarin should be like, and I can tell the difference between "shí" and "shì" if said next to each other; but cannot tell which is which if I hear them in isolation.  

And I lived 13 years in the US, but yet I cannot tell "man" from "men" unless they are said next to each other.  The phonetic pre-processor in my brain still maps both vowels to the Portuguese "é" (Italian/French "è") before sending the word to the lexical lookup engine...

But someone who lived in "China" long enough to find the VMs source books and transcribe them must have gained a minimal mastery of the tones.  Unlike the distinction of "man" x "men", distinguishing the tones would be essential to any understanding.