No you're not. As the umpire, you have no authority over the fan. period.
Unless obbay misquoted the rule book, which he didn't, it appears the ump does have some authority over the spectator. It's there in black and white.
You can try, but you are in a no-win argument. Real simple, the coach states he was directing HIS/HER runner. You going to call the coach a liar?
LOL. You understand the umpire/coach relationship, right? This isn't a court of law where sides are arguing their cases for a judge or jury to decide. This isn't an "argument" as you put it. The ump makes the call. He doesn't call anyone anything. The coach lives with it, and if he can't, he is off the premises. Pretty basic, really.
Like it or not, the player's have a responsibility to know the game and what they are supposed to do and the coaches job to get them to that point.
Nope. Read the rule again. In fact at a tourney yesterday this type of thing happened. The first base coach started yelling dropped ball on a third strike at 10U in order to confuse our catcher and have her throw down. The ump immediately called the out, the ball dead, and walked down to the coach and explained the rules and gave him a warning.
There is no place in the game, certainly at the younger ages, for fans and coaches being described, or you either if you condone or advocate such behavior.