This is an incredibly cool Showcase of the power of Unix command line utilities and their composability. However, I have to say, as someone who recently got into amateur system administration for a server that hosts several services I and my friends use m, I would not want to be responsible for maintaining this!
Yeah in the tests I ran while designing it, it became apparent that keeping everything in order was kind of a pain. However, with Guix it actually becomes quite easy. There is not "state" in the system: the system is simply a function of your system declaration (the /etc/config.scm file) that defines the whole OS. No need to remember what to chmod chown, etc.