From what I have experienced through rec and travel ball, the people that create the most drama are usually parents of the kid that is near the bottom of the skill-totem-pole on the team. I have seen many parents try to "talk down" the talents of some players on the team in order to uplift the opinions of their own sons. Unfortunately, it only takes one of these to spread it like a plague through the stands.
True "daddy ballers" are easy to spot after a very short period of time so there is plenty of time to make a change if you cannot live with it(in travel ball that is... nothing you can do about it in rec ball).
If you son is that fast you are wasting his time at 1B unless he is a giant. Sounds like an athlete to me who needs to be playing Center Field or SS. In high school coaches will find the big huge kid who can only hit for power to play 1B, the athletic kid will be moved to positions that require speed, sort of like you did when coaching.
The good news is the older your child gets the less prevalence of Daddy Ball . Once a child reaches high school it comes down to talent. The coaches are their to win and the best players play in the best positions. In the summer when coaches aren't involved you may have a little daddy ball, but usually the coaches have some influence over these decisions.