Good stuff Jeff, and a comprehensive guide. The only other think I think you could have mentioned is to avoid dynamically generated code, I thought you had it in point five but not quite.
I see quite a lot of people who let wordpress, blogspot or their word processor generate their code from text (have to admit I’ve done it myself at times). It works but the code is messy and there are always a lot of redundant tags which search engine algos don’t like. Doesn’t have to be coded by hand, there are plenty of good, free html editors that will build lean, mean html5 quickly and offer an excellent help facility for the inexperienced. I use the free offering from https://www.coffeecup.com/ but there are many to choose from.