well yeah none said that directly, but you can realize it through some replies.I don't think anyone in this topic who posted 100% has said that their website(s) is perfect?
These calculations are purely for on site SEO. There is a lot more to SEO than just what you do on site, but this small list should be one of the first things you do to a website and work on with the off site SEO after you have these completed. Just my opinion of course.
I totally agree with you, but setting them up without building strong links refer to your site won't help.Those are the basics and you should have them setup, specially the sitemap.