Sweet PDZ is zeolite, a mineral that absorbs odor and moisture. It comes in both powdered and granular forms. You want to use the granular form only. You can also use substitute products like stall dry. Always look for the granular form. You basically spread about a 1/4" thick layer on the boards and use a metal cat scoop to just scoop up the nightly poop load and put it into an old cat litter bucket. You never have to completely change it out.
One little vent isn't going to be enough. When designing a coop, you need to try to incorporate as close as possible to 1 square foot of permanently open ventilation per bird. Then you can open up additional windows in the summertime to get even more cross breezes around the roost. If there is any way to open up a ridge vent on your roof that would be very good as well as opening up the soffits at the eaves. In addition to that, I also use large gable vents.
What general area are you located in? If you live where there are very cold winters, I would be very concerned about the moisture from the birds respiration condensing on the underside of the roof and dripping back down onto them. Without adequate ventilation to remove that moisture, that's a real risk.