Up to where I read, this is excellent advice. Especially the "Unpaid volunteers will, more often than not, give up when things get hard. They may also not tell you that they’ve given up and waste a vast amount of your time." is something I burned myself with many times.

But way too long as a blog post: I would would suggest to break it into many posts, or even publish it as a free ebook and just link it in the blog.