Very good posts.
I think most of the time the parent is a lot more upset about the amount of playing time, or the batting order, or the stats, or whatever, than the player is. Often the player understands better WHY he is not playing, or is playing where he is. And the parent's first job should be to shut up and not make themselves and their son miserable. Second job is to watch the game, enjoy it, and applaud their son's team and teammates. Heck, go ahead and applaud a special play by the other team, too!
Just let your player play. It's the best game in the world.