I should have clarified this... I'm building this trailer for dual purposes.
As a camper it will have a bed, etc. But when not using it for that, I'll be using it as a traditional cargo trailer for hauling around a Honda generator, a 16'x25' inflatable movie screen (it's huge -- two stories high), sound and video projector equipment and a popcorn machine, along with all the cables and tables needed to show outdoor movies. Think backyard drive-in movies. I'd leave all of that equipment in the garage when camping.
In fact, I was considering mounting the projector inside the trailer somehow, perhaps behind a hatch, so that the trailer becomes the projector house. It's of a theme -- I'm lazy and would love to set up things so I pull up to the venue, push a couple of buttons, pop a hatch and the popcorn machine's already churning out kernels and the intermission trailers are running.
My thinking about the generator was only when using the trailer for movie night and the trailer would otherwise be empty. But I've since learned from all of you guys that running either a generator or a camp stove in the trailer is generally a bad idea. Besides, I've got too much invested in this to mess it up with gasoline fumes, etc.