OK, can you cite a few?
Agree. There are advantages and disadvantages to either.
I'm none of those things. You can't reasonably compare any of those to a private citizen carrying openly- apples and oranges.
I know. I was there. Also, I never had time to make an expression, startled or otherwise. It took me a second or two after they passed before I realized what he was up to. And that was with me watching them and aware of my surroundings. The direction my face it pointing has little to do with the direction I'm looking.
That's good, you're far ahead of most parents/grandparents in providing for the security of the children in your care. However, you have a small gun in a caliber that is unlikely to stop a pit-bull or other powerful dog, which is probably your most likely threat there. Open or indifferent carry allows a larger (and easier to shoot) gun in a more optimum caliber. Open carry is far more likely to prevent that pervert in the trench coat from doing something traumatic to the children. Open carry is more likely to deter the carjacker from approaching after the kids are in the car. All subjective of course. Being armed is #1 and you have that covered- good on you.