IMO, it sounds like you're doing a great job. I coach Masters and summer league and all three of my boys swim summer league with my team. I have a hard time figuring out how to be their coach and their parent but have found that letting other coaches do the coaching has worked the best. I also have to remind myself that the enjoyment of swimming comes from the journey (not the arrival). My youngest spent the first two years on the team refusing to breathe to the side on freestyle (he'd always lift his head). The other coaches and I worked with the group on that skill and most others got it. I figured he'd eventually catch on and, lo and behold, he breathed to the side from the beginning of the season this season without being told to. Go figure.
You're doing the right thing. Let them own their own swimming experience.