Glad I could contribute something.
If you want more tips: Choose the channel that suites you best. If you like arch, you probably like rolling distros. You could skip the stable channel and go for testing or unstable and that’d provide you with an experience alike a rolling release model. That isn’t officially supported… Debian focuses on getting security patches into stable, not necessarily the other channels. That’s why only stable is recommended. However, the other ones work great and Debian usually do a good job with keeping them well-maintained, too. I run testing on my laptop and I like it.
(Edit: And Debian should have a good amount of customizability… You can (re-)configure the package manager not to install recommended or suggested packages, and you can also skip the manpages and documentation if all you want is a small system.)
Refurbished Dell 7390? ~$250 has an 13" display with relatively small bezels. I think if you want it even smaller, you’d need some mini laptop or a tablet or steam deck. But that has other downsides. And having a device with an full-size keyboard is nice if you want to type / code.