I pull a 8000lb (loaded) trailer with a 2011 Tundra Crewmax (5.7L with tow package) and have 10K miles so far.
You are right to consider the full loading of the truck (passengers, gear, and hitch weight). But also keep in mind, Toyota rates their trucks to SAE J2807 which already accounts for the weight of a driver 150lb and passenger of 150lb plus 100lb of "stuff" (see SAE J2807 section 3.2.2). But, it does not account for fuel (I use 6.3 lb/gallon for 91 octane/ethanol blend) in a 26 gallon tank (as you mention) plus 100 lb for the sway distribution equipment plus other people and personal stuff.
The SAE J2807 standard only measures how much trailer (& truck) weight can be pulled up ~3.4 degree grade hill at 65MPH for 11 miles with the truck Air Conditioner at full load. I would never go that fast up this kind of grade pulling a trailer as it would cause premature wear on the truck. But that's how this standard is applied. It also accounts for how the trailer is configured during the test and stopping capability.
As long as the weight distribution is properly configured and trailer brakes are working fine, your weight sounds very reasonable. Happy trails.