I'm impressed! You have done a great job of your calculations.
Basically, with a pin weight that high, DRW would be the way to go, as the extra payload capacity would keep you in the clear right across the board.
My big question though, is the pin really that heavy, or is that estimated. As for the truck carrying that amount of weight, the limitation is the rear tires. The rest of the drivetrain is the same for SRW/DRW.
Under the circumstances, it may be necessary to weight everything on a scale to find out what the actual weights are, as these are what will determine the legality of the setup. It may be necessary to move some items for the truck to the back of the trailer to meet regulations if you stay with SRW.
In the end, it is not about what the truck 'can' handle, but more about the rules and regulations.
I wish I could have found an error in your calculations to bring you some great news, but your math and understanding is better than most.