The question shouldn’t be “Is he being rude according to Americans/Japanese tastes?” He isn’t trying to appeal to people from these cultures, but to the Senegalese he’s rooting for, right?
So the question should be, “How do Senegalese feel about this man’s mimickry of them?” We’ll have to ask a Senegalese how they feel about it.
>> We’ll have to ask a Senegalese how they feel about it.
As I said, his “message” is not for the Senegalese but for the people around him. But, OK, someone go ask the Senegalese and the rest of us hold our horses here for a while. I can’t be the one to go 'cuz my mom said we’re having dinner early tonight.
On a related note: Polite Japanese manners.