Great article Justin (and you have the t-shirt on this one, of course).

One other thing to consider is why you're building this theme and where it is to be deployed. The theme on my current site is a mish-mash of Automattic themes; but as the theme is only for my site I pulled out all the code to do with the Customiser and anything else I didn't need such as some styles and Page templates.

On the other hand, I'm just revising by sister's home baking business site, which uses a child theme of a theme by Anders Noren. Here I've left the parent theme intact in case she asks for something it can deliver. Like all the other themes on wordpress.org and .com Anders's theme are customisable by the end user, so you'll need to include that functionality of you're thinking of selling or submitting it.