I should clarify; if there were even the slightest chance of a crying kid, there's no way I'm taking him. Nor is talking allowed. We always sit in the aisle so we can make a quick exit if need be. Discussion always happens outside during bathroom breaks or after the movie. I can't stand going to movie theaters anymore for the same reasons you stated (I've found teenagers and barely 20-somethings to be much more disruptive though). I go for the early Sunday matinee to avoid the crowds. If it weren't for my kid wanting to go, I wouldn't go to movie theaters period.
Sounds like you do it right, I applaud you for that.
I hate going to an early show and see people bringing kids in a stroller or even babies wrapped up in blankets into the theaters. I don't know how they can even enjoy the movie because of the loud noises startling their kids and they start crying. You are also right about teenagers but you can put them in their place and not feel bad about it.