edit: I don't know if it is OK to be editing published articles but I'm a bit of obsessively compulsive perfectionist and I plan on improving it for publishing it in lesswrong, so I am going to take liberty at improving some of the points but perhaps also removing the duplicate argumentation and cutting down the verbosity.

I think it's definitely okay to edit published articles, provided that the editing 1) is small scale and simply adds clarity or fixes typos and does not interact with any existing comments, or 2) it is made plain what editing was done.