Wow.
Pretty harsh. Not so sure I'd want my kid on a team with some of the methods spelled out here. Kinda tends to s-uck the joy outta the game.
I'm sure there have to be ways to encourage heads up play and hustle without resorting to some of these tactics.
To start off, each girl should have assigned duties. I've watched a local, very successful and respected college coach during practices and games and each girl knows what she is responsible for and is expected to do these tasks in an expeditious manner (gathering/organizing equipment, raking the field, picking up the bases, assisting catcher with gear, policing the dugout for trash, etc).
This sense of organization is carried through into play on the field. They are expected to hustle off and on the field, no walking allowed. When not on the field, they are to be watching the game and cheering their teammates, not chatting idly.
I don't think you can make "punishment" sprints or sit-ups a consequence for errors or mistakes... You can't have them afraid to make mistakes because then they will be afraid to really play flat-out (which is what I would want to encourage). You can't play carefully.
If a girl is not performing her tasks, not paying attention, willfully disobeying a directive...then you sit her. This is the worst punishment you can mete out to a real player.
Not much can really be done about a bad inning out on the field. The best you can do is try and stop the hemorrhaging. I can tell you that a chewing out never helps. It might make the coach feel better, but will only further demoralize the girls. Believe me, no wants to get out of the inning more than those girls. What they need is calm support and some reassurance, not a "butt chewing".
Attitude of the coach is paramount. These are 12u girls, and it is their very nature to be distracted/petulant/scatterbrained/willful. It's their job...and they are very good at it. But they're on the team because they want to play and they want to play well. It's up to the coach to try to give them the tools and organization they need to make this happen for them....but it has to be in a way that keeps the game fun and fresh for them, or why even bother?
jmho