In re: ventilation you need to be thinking square FEET not square inches.
Overcrowding is the one factor most likely to ensure that you won't enjoy your chickens because it causes both behavioral and sanitation problems.
Some people in VERY forgiving climates where chickens have full access to...
Welcome to BYC. That's a cute little brooder for your babies but you'll need a much larger coop as they grow up. :)
Using the dog kennel for the run is great -- spacious and sturdy.
Where, in general, are you? Climate matters, particularly when it comes to housing, so if you put your location...