A generous guide Edwin with some very useful tips and good advice.
I do think that this document should maybe be coupled with a 'How to spot whether you website has been coded properly' document.
I know I am always banging on about well structured html documents, not using tables for layout, proper use of heading tags......e.t.c, but this is what google reads, the html document, and unfortunately a lot of people completely overlook the quality of the code and are more concerned with what the stock photo in the header looks like or how many adsense ads they can squeeze on a page.
It is unfortunately quite often small local businesses that fall foul of badly structured html, and out of date coding techniques as the owner will more often than not know nothing about website code.