I think the sales guy was pretty much right on. Also reading what your plans are you should have no difficulty.
Couple things to consider though. If you think you might want to do a little dry camping consider adding two additional batteries and or a 240 watt solar panel. Adding 2 X 240 watt panels will cover all its needs.
Also, trying to calculate the fridges uses by the plaque data in not realistic. The plate will show what the fridge draws on start up which is a fraction of a second. It will also not show the duty cycle which for ours is about 30 to 40 percent. Our fridge draws just over 1 amp from our inverter when its running...which is about 30 to 40 percent of the time.
You will NEVER not EVER regret having a residential but depending on your usage you may have to outfit the rig a bit to deal with its needs.
Good luck...happy camping.