Ja rodgers I have read some of his books especially the book greatmen of color,but many times rodgers misses the mark when talking about different subjects. I still recommend his books,but with today's anthropologoy i recommend you take ja rodgers words with a grain of salt.
On the other hand alot of Ja rodgers claims have proven to be true. The one he got wrong was about cleopatra which was not egyptain,but actually macedonian.

I don't know what to say about the sumerians except I have seen their sculpture and none of it looks africoid,even the most sense.
You might want to look at the standard of Ur,and you will see these people do not look africoid. I amaware that nimrodis the founder of babylonia,but we have to take in consideration the bible is not actual history.
many people believe nimrod could have either been saragon,or gilagmesh I have no idea though.
As far as the black chinese question.I am very unsure about this comment that the shang dynasty was africoid. I have seen africoid pictures,which are probally melanesians. A chinese archeologist has confirmed though that socaleld oceanic negriod were the first to inhabit southern china.I believe there isa people there called naki if Iamnot mistaken.You have to be careful with clyde ahmed winters though and someof his work is kind of questionable.Winters claims to have deciphered meroticandthe indus valley script when most people have not.
Clyde ahmed winters isnot my first choice when it comes to scholarship.
As far as your question about chinese coming from china. I donot believe this,because ithas been shown that possibly the native americans could have even come form polynesian stock. The oldest culture at one time was thought to be the clovis,but they are finding cultures older than the clovis around vigiina.
NAtive americans do share alot of similar features with those in siberia,which it is believed they migrated over during the last ice age.