Well, for starters, if you're just using it as a grow out coop, you probably can do away with the nest box, and just screw a piece of plywood over the hole. That might be a good place to add ventilation too, as long as the chicks are not sitting in a draft when on the roost.Those prefab coops only use small staples to hold the hardware cloth, you would do well to reinforce that with screws and fender washers over the staples. If you can't get the one area of hardware cloth to go back in place, I'd just replace it, You don't want to try to patch it. It needs to be taut to prevent animals getting a good grip.I'm not familiar with the material for the roof, so can't comment there. The usual recommendation for a skirt is 12 to 24 inches. Sliding latches are easy for raccoons to open, I would add a safety hatch and lock or carabiner.