You are kind of the opposite of us when we leave our Florida home during some of the summer months. We leave the air set on 80 and worry about too much humidity instead of not enough.
I'm not sure I would shut the air off. My BIL lives in Arizona so we know how hot those daytime temps can reach. Not sure I would want the inside of my house to consistently be getting up to 100 or 105 degrees.
We put just a little bleach in our toilets and put siran wrap tightly over the bowls. It keeps the water in them and stains/mold from forming.