Gustafson’s article can work like a tutorial to help you accomplish the bridge between accessibility, and usability. The article inspires me to keep learning and looking for ways to combine both accessibility and make it usable for the visitors to. Sometimes we never give the users any credit they are smarter then we think, but we need to be careful not to make our site a chore to navigate, because in the end content will drive visitors, and helping them get there is the web developers job. In the end this article helped me understand how HTML and CSS is just the bread and condiments of your web sandwich, there are many different meats and toppings out there. Making the sandwich delicious is a different topic, but always keep looking for new knowledge.
To get some JS and DOM knowledge check out this book