I run unattended-upgrades on all the debian/ubuntu deployments I manage. One of the deployments even has automatic reboots enabled. I still do major upgrades by hand/terraform, but the process itself works flawless in my experience.

Syslog is what you are looking for.

SCO OpenServer

See a search engine and do some research. Maybe try out a bunch of different distros and find out for yourself

We have a bunch of these at the hackerspace. They run vanilla debian and connect to a terminal server using xdmcp. Works like a charm.

Some script that parses blocklists into unbound local-data statements, combined with cron and unbound-control