[Western Traveler]

A lot of needed information before you can get reasonable answers to some of these questions. Size of generator and the air conditioner unit will determine if the gen will handle it.
Where you are camping and if you can take water or hit a dump station along the way. It sounds like you will be in more than one place.

30 gal is a pretty good load of water unless everyone is taking two showers a day with the water running steady. Many folks take a "boat shower" when dry camping (wet down, turn off, soap up then rinse. Can be done with 1 gal. If you look at the shower head there is a slide bar that will turn the water off at the head. We use two shallow plastic tubs for washing dishes. We wipe dishes, soap up in one and hot water rinse in the other. Type of place you are staying will determine if you can discharge gray water. Think of tent campers and how they handle things. Use Biodegradable soap and discharge well back from lakes, rivers and streams. Most highways only allow discharge of clean, clear water. Most "parks" don't allow it but many have wash stations and your waste water will be going to the black water tank as well as your 30 gal gray water tank.
Two of us used less than 20 gal on our last 6 days of dry camping trip.