After my 3rd year back (off of five years after 6 years on) I developed a very thin skin and I was tossing people (not just coaches
) left and right. During the off season (in Socal that's between Dec to Jan) I had to really think about if I should continue. 10 years later and I am glad I continued. In the last ten years I think I have eject 10 coaches. My goal is to keep every one on the field. Yes there is a line but I
professionally put an end to it before it gets out of hand. A lot of times it is as easy as walking up to the head coach and saying, "I've heard you (your coaches), now let's play ball." You can even use this in your situation with an older player. The bottom line is you professionally acknowledge them and then polity tell them to move on.
I think the 3rd year of umping is the toughest. You know your mechanics and are very sure of your judgement, but you may not be 100% on all the rules.
Here is my funniest ejection. I called a high strike on the daddy coaches DD/F1. The next half inning I did not call it for her and daddy started chirping. After the half inning ended I went to the coach and told him that I made a bad call, and it is time to play ball. He told me that I was going to have to eject him or he would continue. I told him nope he was going to have to tough it out.
At that point he told me he was ejecting himself. Before I started the inning I turned around and he was behind the bleachers. I looked at him and said, "Coach you ejected yourself. You need to go to the parking lot." He went.