Welcome! By asking around about these things, you're setting yourself up for success. Here are some of my thoughts:
Words matter. Prof mom had some good suggestions. But even here, you used the words "dealing with" which sort of sets up
an adversary relationship. I'm assuming that most of your parents aren't overly pushy and you really meant communicating?
Let parents know the best way to get in touch with you. Some people prefer phone, email, text, or in-person. Go with what you
want, but make sure there's time built into the day/practice for this to happen. It's sometimes hard when a group of boys is
finishing and another group is starting. So in-person communication can feel rushed.
Our coach sends a weekly email that's really nice (and makes other parents here jealous). It's never a big deal. Usually a reminder
of practice times, updates on meets or payments, and often a "video of the week".
- sensitive/emotional gymnasts
Back off. Give the kid space, but check in after a while. You should never say things like, "There's no crying in gymnastics" or "man up".
Ask, "Do you need to take a break?" or say, "Why don't we stop this for now and try again next practice?"
Busy kids don't get into trouble. If you're trying to work with a lot of kids at once, set up stations rather than having a long line of
kids waiting their turn. If you're getting back-talk, try to find out what the real issue is. Remember that kids aren't inherently jerks,
but they can act that way when their needs aren't being met (and needs might be hunger, a feeling of control with school, or a sense
that their coach values them as a person.)
- lethargic/apathetic performance
Some kids just aren't that into it. Sometimes you just have to respect the fact that just as you'll have some kids who are go-go-go
at gymnastics all the time, you're probably going to have a few in the program because they like the tumbling part (but don't care
for other apparatus) or who are just there because a sister does gymnastics and it's easier on the parents if the boy does it too.
Sometimes a kid will appear apathetic because he doesn't think that he could ever be as good as the super-star kids, so he doesn't
feel like he's a worthwhile member of the team.
Our coach ends each practice by having each boy say something he did well that day. He focuses on the kids as they speak, then shakes
their hands after. I think that really makes the kids feel valued and he has a lot of kids who work hard but will probably never
be stand-out gymnasts.
Another idea to pull in that doesn't necessarily fit into your categories is the idea of growth mindset and/or grit. Those are popular
concepts right now and gymnastics is the perfect opportunity to learn perseverance.
I think it could also be helpful for you to get a general sense of proper child development. I mean, I know you've been through it
but a lot of adults don't have a good sense of where kids should be at different ages, and this sets up unreasonable expectations.
For instance, if your behavior problems are occurring in a class of 4-6 year olds, you might need to have a faster pace when it
comes to switching the activities.