One additional one I would add is: don't be an ass. I have seen a fair share of people in this role belittle QA, Devs, and interns because they're not able to follow along or understand how to use DevOps tooling.

I like to think of the role as hospitality; you don't particularly have to like the guest but try to create a good working atmosphere.

A specific example: if a particular dev runs to you every time a build fails and tries to blame the environment: force them to check their own work first. If there's another branch that builds, ask if it's related to one of the changes in this branch. Ask if the code builds locally. Ask them what they've tried so far to debug the issue. These questions will help out anyone who does not know how to actually troubleshoot build failures and discourage anyone who is simply trying to pawn off their work.