fischer, way to go with your close eye on the flock. Good flock management is always making sure the ones in your care, are being taken care of in a win, win, situation for you and the birds.
I'm thinking that your insulated coop with less than really extreme temps would work fine with the light being set on a timer.
I use one when i choose to extend the light hours to the optimim 14 hours for laying.(sometimes it's good to give the flock a needed rest)
I chose to raise a backyard flock to benefit the birds, creating the environment God ment for them. I would never alter my birds for any reason....that's my choice, and yours too!
Their sunflower seed and cat food is mixed with cracked corn. Nutritionally I feel pretty good. When we have been way below zero I have kept them locked up. However, after a couple of days they are a bit nuts in there! So I leave the hatch open a crack so they can go in and out. Although when it is real cold they just stay in on their own. Crazy birds!
We did get rid of our Easter Egger rooster which seemed to be most of our problem. He was very aggressive and quite a feather plucker but the girls seemed to learn some of his behavior.
Have you tried hanging those little bird seed bell or the bird blocks? It gives them something to pick at besides eachother, some others on here have hung melons and squash as well.