Is your fridge a residential style, or an absorption style (uses propane)?
The reason I ask is the residential style tends to have a built-in defrost mode, the absorption ones don't (that I've ever seen). Consequently, when I lived in my first Class A for a year, I'd have to manually defrost the freezer about once a month. With the residential style, no such issues.
I had my first Class A for 1.5 years. It was always powered up.
My last Travel Trailer was parked in storage for part of its life, the rest at our current home, which I've added a 30A connection. It has been powered up since 2006. I sold it last week.
It does NOT harm an A/C to leave it running. Seals tend to fail from lack of use, rather than overuse.
The humidity and heat will destroy the inside of a camper here in FL. But setting the thermostat to 80F, will keep it pristine inside.
Our current Class A was purchased last November, and has one A/C running the entire time. I'll soon be changing my RV outlet on the house to a 50A, so both units can cycle as needed.