I alway feed growing layers as much as they want to eat. Keep the feeder full and Don't limit them until they start laying. Once they're laying, limit feed to 4-6 oz per day. Hens in lay can over fatten, especially dual purpose breeds. Once they're too fat, they stop laying.
This is from the USDA website concerning Organics. I'm not trying to prove anyone wrong, I just thought someone might want to see this.
"The use of genetic engineering, or genetically modified organisms (GMOs), is prohibited in organic products. This means an organic farmer can’t plant GMO...
Air chilling can be tricky. You want to make sure to get the carcass temp down to 40•F ASAP. I think within 2 hrs of kill. Putting them in a freezer would speed up the chill. Air chilling does eliminate added water weight.
Butcher paper should work. You might find something reusable.
Keep limiting there feed. One night away from feed shouldn't hurt.
Males and females that age look almost identical when you butcher them. Older hens butcher the same way, it's just a little more... Interesting.