Very nice! Particularly that you also mention some important aspects of how to secure it. Many people seem to forget about security, so it’s nice to see that you didn’t.
What I would definitely add to your instructions is a section about log management and in case of a Raspberry Pi, the problem of only using an SD card. When not using an additional drive, storing all your logs will quickly degenerate your SD card, especially when you decide to use Fail2Ban, which will generate a lot of log files. I’d suggest reducing what is logged or using a Syslog server, but even better would be just mounting an HDD so that those logs are not a problem anymore.
But Kudos for these instructions, it’s very well written and I will definitely recommend it!