Hi Andy,
Glad to see you're posting some more info on your bus!
Give some thought to where the breaker box ends up in the bus; in your layout the rear location might work out well but in general that would mean very long runs of wiring (heaveir, more expensive wire) to get to the front part of the bus. If the box is near the center of the bus then you have shorter runs toward each end of the bus.
It's not a great idea to put more than two outlets on one branch circuit or more than one outlet and up to a 15-amp load (like a small battery charger or something). The reason is that unless you're going for a high-end 50-amp shorepower system you'll most likely use 30-amp stuff. You can get yourself into a situation pretty easily where you have the outlets you need but not the amps on one circuit.
Here's an example...we've got 30-amps available to the bus via shorepower. We have one branch circuit that has two outlets on it; that branch circuit is protected by a 15-amp breaker. Each of the outlets is rated for 15-amps as well. So lets say we've got a circuit running from the back to the front down the driver's side with an outlet in the bedroom, one in the bathroom, one in the kitchen and one far forward. We're plugged into shorepower and we decided to use a 1500-watt plug-in space heater rather than run the propane furnace. So now we're drawing about 13-amps from our far forward outlet (1500 watts divided by 115 volts to get amps). It's time for coffee and we want to turn the coffee maker on in the kitchen; it pulls 800-watts or 7 amps. Uh oh, that's going to trip the 15-amp circuit breaker that our outlets are on. But we're only using 20-amps total; less than what we're getting from shorepower by a wide margin. Instead, if the kitchen outlet were on a circuit of its own we could run our heater and the coffee maker and still have some left for the TV or whatever.
You want heavy loads (like a coffee maker, microwave, heater or battery charger) on their own circuits; it's ok to put a couple of outlets on one circuit if they're for light use or typically wouldn't be used simultaneously. Like you could have a portable radio or TV plugged into the bedroom outlet and an electric razor plugged into the bathroom outlet on one circuit and still have lots left before tripping a 15-amp breaker.
Hope this helps...