If you exhaust out that with the duct fan in the front over the door, the other 2 vents will provide fresh(or makeup) air. Just have to make sure it doesn't cause a strong draft on the roosts.
I have no idea how much CFM the duct fan will move and how it feel inside the coop with it...
Covered styrofoam on the 'ceiling' would help-kinda, but it wouldn't solve the real problem which is too much moisture...an exhaust fan would be awesome.
Horizontal nipple waterer and scooping the poop everyday would too.