how to catch batter being out of batter's box

[bniu]

I had a recent game (16-0) where the losing coach jumped all over me about a batter being out of the batter's box. This is a coach who's pitcher couldn't find the strike zone if I spray painted the strike zone for her. He seemed to be far more interested in nit-picking the rules with me rather than coaching his team because his team was just AWFUL, i've never seen more mental mistakes combined with a lack of talent in all my games. I really wanted to tell him: "Look at the scoreboard, if you spent half the energy you're spending by arguing with me, maybe your team would be somewhat competent..."

Anyways, he then jumps on me for calling a borderline pitch by his pitcher a ball, which I have to admit that I kinda froze on because I was surprised his pitcher actually threw something that good. Another problem was, the previous batter maybe had been slightly out of the batter's box when she hit a grand slam, and he jumped on me for that, so I stared at the batter's feet and only saw the pitch out of the corner of my eye...

so how do you look for the batter being out of the box? some of my senior umps tell me that the batter has to be all the way at the pitcher's circle before they even bother calling it...of course they're exagerrating but usually, I may take a quick glance at where the batter is after the hit and if they're reasonably close, I give it to them...since it is something that is in my peripheral vision, if i see it, i see it...

And he also argued with me on that new bunt attempt rule. The opposing batter held out to bunt, and just as the ball came, she started to pull back, I figured, good enough for me, Ball! What exactly is the ruling on that? I figure if the batter starts to pull back, it's good enough for me since the rule never said that the bat has to be withdrawn "completely" from the zone, so I interpret that as a "start to withdraw" is fine...