I won't stray into the debate over the validity of the chart - as that wasn't the OP's material, nor is that the point of his article.
Please don't take personal offense from this - especially since you effectively waive your right to an ego by askingfor feedback - but if I'm honest, this is the kind of article which I would say is the problem with the internet - limited experience and expertise, yielding slim to no actual aide or instruction in the subject matter it's trying to convey. After almost 20yrs as a handgun instructor, developing coaching plans and training materials to present this very topic, I can't see anything of substantive value in your article to help a shooter rectify a technique problem. Largely, you could replace the subject matter with almost any physical activity and the troubleshooting process would be the same - so the article isn't about shooting, it's a boiler plate process for any activity. "identify your problem, determine an appropriate solution, practice, measure your progress, and don't be too hard on yourself - plus by the way, here's a really old handgun symptoms chart..." - that's what I read out of the article. Anyone can get published online these days, and having only read this singular sample of your work, I don't judge the entirety of your knowledge base or your body of work, but any time I have produced that kind of article, I ask myself - "will the target reader be more knowledgeable in the subject matter for having read it? Will this help solve their problem?" Envisioning myself in the shoes of so many students I've helped through specific fundamental technique issues over the years, there aren't any answers in the article beyond the (obviously controversial) handgun errors chart which has been around for ages.
Beyond the lack of substance, there were multiple grammatical errors which any common word processing program should have caught, but since yours didn't, it distracts the reader from the subject matter by forcing them to decide what you MEANT to say, instead of reading what you said.
Again, I really don't mean this as a personal insult. If you posted here asking for feedback not actually wanting it, but as a veiled attempt to advertise your article, then that's a new ball of wax unto itself. But you asked for feedback, so I will hope you take my comments as constructive criticism, even though my honest feedback isn't positive - I don't think reading this article would help a struggling handgunner solve their issue, which was the point in writing it, yes?
There are LOTS of peer-review websites out there where other professional writers will help you develop your writing technique and help drive a more productive and successful product. It's in these arenas where the bloggers get separated from the writers - and not all of them are as callus as I, so consider that good news!