Love the solar fan idea.
If you live at lower elevations in AZ, your "heat-index levels" may be more important than predators. Having a coop in southern NM, I worry about how hot your coop may become inside during summer months.
Can you provide some additional ventilation, above & "below"? Possibly insulate the roof from inside the coop)? Smaller mesh wire at least on the coop openings would prevent wild birds, mice & pack rats from eating your feed. Dogs rarely care about the sleuthing mousie, and can not reach marauding birds (that also can carry disease/parasites).
It would be nice to shade the nest boxes, possibly deterring a build up of heat within the "cubicles". You may have Fried Eggs........