Ehhhhh... It depends. If it's someone I've seen a dozen times, and I've gotten the impression that they're reasonable people, then I might answer their question. Otherwise, hell no! You're nuts to address the peanut gallery.
Sounds like this coach is just "one of those." His complaints have NOTHING to do with rules, only a gripe about "consistency." It's an easy insult to throw at an umpire, and it's almost indefensible. Kind of like getting called a racist - it's hard to "prove the negative" and show that you're NOT that way.
And for the record, the safety base is an appeal play. It's the defense that has to ask for the call to be made, and I RARELY see it in a rec league. Maybe once a year do I actually get asked, if that.