If the orchestra is playing for 30 seconds at the beginning of the show, I don't think that's really an overture. It's more like a prelude or something.
I believe that US union rules are that all fights/stunts have to be performed every day prior to the show, just to make sure that everything is as it should be. I remember one of the Spring Awakening cast members saying they had to go through the fight in the second act before every performance, and that was a pretty minimal fight. I think it's a good rule, although it takes time.
"What was the name of that cheese that I like?"
"you can't run away forever...but there's nothing wrong with getting a good head start"
"well I hope and I pray, that maybe someday, you'll walk in the room with my heart"