What riots? This was a man selected by the Jewish people to be executed. Why would they riot about it? And killing him quickly negates the whole purpose of crucifixion, which was to humiliate and torture the victim for as long as possible, as an example. No, from an historical perspective, the whole story makes little sense.
Yes, but he was also Jewish. He would have relied on any documents, especially those coming from Jewish sources, and as near as we can tell, the only documents which referenced Jesus came from those Jews who were his followers, the first Christians.Why? he was a historian, simply, not a religious person.
Quality is probably not the right word. Experts can usually tell if something was written by a person, especially one as prolific as Josephus. They have many examples of his works, but those short bits which reference Jesus don't seem to fit his style. And they are only one or two short comments, something similar to an historian referencing someone like King Arthur, or Paul Bunyan.I am not sure what you mean by 'quality'? But it seems to be just a short notice, anyway.