I have been towing since new with a 2007 Tundra 2WD TRD. The rear axle weight rating (and it is more than your 4WD) gets exceeded very quickly if I am not extremely careful. My fresh water tank is fwd in the trailer so I try to go with a minimum amount of water and tank it up either at the camp ground or if boondocking out in the desert, as close to my highway turnoff as possible.
Just because the truck will pull 10,000 lbs., doesn't mean any of the other specs will be met doing that.
Also, when figuring any weights, go by the stickers on the vehicle, not the manual. The stickers reflect the actual build of the truck, the manual is often more representative of what was engineered than actually built.