With respect to paid promotional editing, I have done a bit work trying to address it. For example I reached out to Upworks the company behind Elance and Fiverr and they are interested in working together on this. Have been a little distracted and not sure if there is sufficient community or foundation support to move forwards.
With respect to using AI to detect paid editing, I spoke with Aaron Halfaker about the possibility in Nov 2015. What he needed was datasets of confirmed paid promotional editors. I have sent him some details. If others have details that would likely be useful. Things are in the very very early stages from what I understand.