Sounds like lots of good suggestions. You might also try increasing effective space in your coop vertically, like installing more roosts, shelves, wooden boxes, or even old lawn furniture, so they have more places to hang out and escape. Four sq. ft. per bird might be standard advice but that sure seems crowded to me, especially if they are cooped up all day. I have only seven in about that space, and they are chomping at the bit to get outside if I am late turning them out. Hope you can figure it out soon. Best wishes.