Sounds like a good plan! And yes, painting BEFORE putting together is really something I wish I had done... I'm having so much fun climbing inside the coop to paint, lol!! I used 1/2 inch screws with washers to reinforce the screens at the corners and every 12 inches, then followed up with 3/8 staples. And I added a 12-18 inch hardware cloth 'apron' around all sides. From the reading I did on this board, I think 1 box per 4 birds is fine, apparently they all want to use the same one anyway? I wanted the extra room to add water inside the coop, although I'm not sure if I'm going to add a pop door or just a dog door type of flap, as I live in a very temperate area, in a neighborhood with few predators, and I think with the reinforcements I've made the entire run should be just as secure as the coop itself... but, if you do decide to add a pop door to make the coop more secure at night, you'll have to add some hardware cloth along the top of the coop where it meets the roof, as that opens right into the run. Looking forward to seeing your mods!!