In general, I agree with the article, but I would like to put in context a couple of points. The first commented error in the article is the famous rule of three clicks. I think it's been a long time (years!), and many studies (including some by J. Nielsen) have shown that the important thing is a good Information Architecture, and not how many clicks the user has to do. On the other hand, I believe that consistency in colors and styles should be seen more as a good practice than as a rule. Of course it's important, and you need to respect it whenever possible. But it's also true that skipping this consistency can lead CTAs to a better conversion, or improve the emphasis on certain aspects of a website content.