Re: insulation, I'd like to suggest that if your shed is in full sun, those metal walls will get hot, regardless of the ventilation you've installed. The west and south walls of my large metal barn, with lots of open doors, windows and ventilation, got pretty hot to the touch in full sun, esp. summer. So I installed those sheets of blue, rigid insulation panels. Made a big difference. I'd certainly consider adding wall insulation, covered with a thin plywood wall, on the south and west exposed sides of the metal shed if in full sun. Plywood will keep chickens from pecking at whatever insulation you would use.
Also, as mentioned, the interior metal ceiling will sweat in certain weather. My barn, a coop and my covered run all have insulation on the interior ceiling. I used the leftover roll of insulation from the barn construction on coop and covered run. Worth doing, IMHO. Just some points to ponder.