Loaded up to camp, your hitch weight will be 400 to 450lb. (The dry hitch weight is only valid when towing empty home from the dealer)
Add up everything you're carrying in truck: 450(tongue) + 60(gen) + 300(scooter) = 810.
Subtract from cargo capacity:1360 - 810 = 550.
550lb is what is available for passengers and any other stuff.
Definitely get a weight distribution hitch to transfer some of the 450# tongue weight to the TV front axle and back to the TT axles. Otherwise, your truck's front axle will be too light and steering will be unsafe.