I would be fascinated to know too. I was also interested in Bantu languages (or in fact any African language group) in the context of the Sapir-Whorf debate. I read Stavros's post about Korean and was trying to think if there was anything similar in Africa, or those parts of it where society is extremely heirarchical.

Sadly I'm absolutely rubbish at all languages. When I was in Cameroon I went to the Fon of Bafut's palace and saw someone disciplined for directly addressing a high-ranking royal official whom he should have approached through an intercessor. The fine was hefty. In many African societies the divinity of the ruler precludes direct communication. Since the visual symbology and ritual defining the heirarchy is frequently so hugely rich and complex I would be quite surprised if the language was not so too.

But I'm still left with the question, which came first - the cultural chicken or the language egg.