I'm very curious about the communication piece. My rule was always simple. I will be open and honest with you. All I expect is the same in return. I am getting some mixed signals from this thread. We want coaches to tell us everything that is going on. Will there be pickup players? If so, why? How will playing time be distributed? Etc. Yet, some see no need to tell the coach about picking up for other teams. Doesn't that seem a bit hypocritical? Just trying to understand...
I'd say that in many cases, it's because families are paying for the "privilege" of having a spot on those teams. Because of that, the team has a different set of responsibilities to the players/parents than the players/parents have to the team. As a coach in an organization with dues, I've always felt that was fair.
That said- my kids' coaches have always known ahead of time if we were picking up (or even trying out for another team), but that's a personal thing that I prefer to do. I don't necessarily feel like it's an obligation.