Actually, instead of a chainsaw, I bring a small bow-saw. Never runs out of gas, no noise, easy to start! And we actually used it this last summer -- in the Jackson Demonstration State Forest near Ft. Bragg, CA, they allowed us to cut downed wood for firewood. Good exercise, too!
I would not consider a 100w solar panel essential. It is not going to put out enough to eliminate the need for the generator so what is the purpose? It would be fine for storage where you have no access to shore power but it is not going to eliminate the generator so why bother.
It depends on what your needs are. A 12v system comprised of two 6v golf cart batteries, a single 120 watt solar panel, and MPPT solar charger is more than enough for my needs. Power for lights, 12v water pump, fans, TV/RADIO, and DVD player is all I really need. I only use the generator to fire up the A/C and microwave and maybe recharge the batteries on a cloudy day.
Now if I had a 40 ft motorhome, like you, it would probably be different.
2011 Wolf Creek 850N/Polar Cub/240w Solar/2-6v Lifeline AGMs/Morningstar Sunsaver w/RM-1 & SureSine-300 Inverter 2011 Ford F-250/6.2L/3.73/Bilsteins/Air Bags/Torklift TD w/Fastguns 2004 Jeep Wrangler/4.0L/5-spd US Navy Ret.
I was using the OP's description of "Essential" and the statement that a generator would be one essential item. If you have a generator that makes a 100w solar panel nice but not essential in my opinion.
Found some round battery lights about 4 or 5 inches across at Home Depot or Lowes that take 4 AA batteries. Real nice to put on the wall in the bathroom or over the couch so as to have a little light without using up the trailer battery. Quite inexpensive. The light is not bright but not bad especially for the short, summer evenings.
Agree a solar array is not essential. Neither is a generator, depending on how long you are out, your battery setup, and how power-conscious you are. My longest without needing to recharge has been 5 days.
An air card? If you have cell or wifi service you are not truly boondocking.
I also question a 7 gallon water tank. That is around 60 pounds I would have to lift and pour into the tank. I can do it, but I would be seriously grumbling about it. You can have a portable pump, but then there is no need to limit your refill jug to 7 gallons.
One thing not mentioned is a set of 7.5 minute topo maps of the area. Downloaded off the internet while in the last wifi hot spot before heading into the hills. Or orthophoto quads.
The arsenal is also subjective. We boondock in some pretty remote areas too. So remote no one ever finds us. No miscreant intent on evildoing is going to cruise the backcountry twotracks looking for easy prey. We also are armed, but for 4 legged pests.
Log off and go camping!