Apparently (drum roll please) the Wash Post broke the story.
The Post report provides possible answers to other questions.
Because Clinton’s team paid for the dossier, it’s likely that she gave it to the FBI, where James Comey planned to hire the former British agent who had compiled it to keep digging dirt on Trump
I understand the POST broke the story. (I can’t get the WP.)
It’s just that the source of their information is, as far as I know, unnamed. Not even as “anonymous”.