I found it funny that number 4 dealt with your tacticool clothing giving you away... and at the bottom of the page was an add for... tacitcool pants...
(Yaeh I know search algorithms usually choose the ad but it was funny!)
As to the actual text... I don't care much about printing, unless I am really trying to conceal, it used to be a slightly bigger deal in Texas, but they changed the law a while back.
On adjusting, I usually do that when I get out of a vehicle, hidden somewhat by the vehicle and the door, lots of people do that, and its not an indicator of carrying. Now in the middle of the isle in the grocery store... maybe thats different. But even then I'd argue the average person will just think you need a better belt, if they notice at all, unless you flash the gun.
I use "cheap" nylon holsters, and contrary to the article they are the "go to" holster for a few of my firearms (and I have them for others). Nothing beats them for the minimalist size which I prefer in some cases. Thats not to say I dont have other more expensive holsters of different designs for some of my firearms. Its just I don't agree with the articles blanket statement. Find what works for you is what I say.
The only other one I had a substantive disagreement with was the first one, Training. I don't think one needs to have training in a formal sense, if they use their weapon at the range, get to know it, learn how to draw it... all that can be self taught. That said, I think professional training classes are great, and I recommend them to people depending on the situation, and I have looked into some as well. My major disagreement is that while I completely agree with the keep learning all the time message in the article, I don't think it has to be formal training as the article seems to elude to.