Hey, sounds like you’re doing a good job already! One thing I want to add is to establish a boundary for the three different relationships you’ll have with your coworker - mentor, personal, and working. You don’t necessarily need to be explicit with him about it, but you should have a pretty clear idea where the lines are for yourself. This is so that you can be aware of when you need to be a mentor, when you should be a boss, or when you should just be another human. Of course those boundaries will change over time, so it’s good to re-evaluate every once in a while.
It’s also good to remember that at the end of the day, you can’t actually change how your coworker behaves - it is up to him to make the choice to not say shitty things, be kind, and do good.
I think beehaw is intentionally not moderated and controlled as a reddit replacement. There are lots of people who are looking for a reddit replacement - beehaw cannot be that for them. Some people get frustrated and speak out, some of them accept it, some choose to move on. The way lemmy works is also fundamentally different from reddit, some lemmy instances look to replace reddit by federating with everything, and that’s totally okay. Beehaw does not do that for moderator and community health.