Here is a few additional things not on your list that I love and have implemented on my blog:
- Plain text versions of all posts. Change the file extension on any page on my site from ".html" to ".txt" to view it as plain text (https://breckyunits.com/intelligence.txt). Makes it easy to copy/paste a whole post into an email or Reddit submission
- View source links at the bottom of every page. Every post is 1 file tracked by git, and I put a "View source" link at the bottom of each page. Even the static pages are also one file, and also have a View Source link.
- Clientside full text search - https://breckyunits.com/search.html.
- CSV export. In addition to RSS, you can download my site as CSV (https://breckyunits.com/posts.csv).
- Keyboard nav. Use the left/right arrow keys to navigate through pages on my site.
- Helpful 404s. If you mistype a url, the 404 page compares it to working urls and shows you the closest match. All done using clientside JS (no web server needed). For example: https://breckyunits.com/pcr.html
- Download entire site and read offline. Everything is designed to work fine locally and you can download the whole thing as a zip. (The link is at the bottom of every page)
- Printable. Everything is designed to look decent printed. Nav elements are hidden via CSS when you go to print. I haven't added automatic generation of PDFS yet, but that is on my todo.