Boxes, for nest boxes? No, they're really not going to work.
Nest boxes need to be private, and they need to have bedding/shavings, etc to make the hen feel cozy and cushion the eggs from breaking. Keeping the bedding in the box means some sort of lip or facing on the front bottom edge, or...
One easy way to add a lot of airflow would be to make a screen door for that people door.
Cut a pop door wherever the run is going to be. Cut more windows, covered with probably hardware cloth or something similar for predator control. Decide where you want the roosts, and position the...