I would like to see all the comments addressing the facts and arguments in the main article, not responding to what commentators have said. This simple rule would stop the thread going all over place.
If one has to respond to what a contributor says better than:
the commentator should use the form, “Some have argued (plus a summary of the point you want to rebut)
Popular posts should be elevated up the thread.
Commentators should have the right to re-edit what they have uploaded. Even though I tend to write my post first in a word document, I nonetheless often upload terrible English which I wish to correct.
Commentators should be able to make one substantial contribution per article. Minor contributions limited to say 70 words would be possible for humorous comment or to inject points of fact.
Posts which are badly written, irrelevant, misinformed and poorly argued should be moved to the bottom of the thread.