we need some recommendations on what setup is needed as a minimum to be actually useful for the network.
The relay guide might be of use to you:
https://torproject.org/relay-guide#RelayRequirements
I've been checking on metrics.torproject.org on stats for my own node, is that the best way to monitor the nodes?
Relay Search does not show you any information on how much memory and CPU usage your relay is experiencing. And it does not send you an email when your relay is down.
For these kind of things other systems are better, but relay search is a good place to see if your relay's consensus weight.
https://torproject.org/relay-guide#Settingupoutagenotifications https://torproject.org/relay-guide#SystemHealthMonitoring