You are well ahead of me in your understanding on the tranny's internals and function. I suspect the "rebuild" you had done earlier, by someone else, was not very good ... based on its early failure and the loose bolts that you found. I cannot suggest any repair path for you to follow.
I know you have already committed time and money to the tranny's repair ... with little good outcome. I wonder if the local Ford dealerships offer across-the-counter exchanges of tranmissions? I have exchanged my broken transmission with a Ford remanufactured transmission for less than $2000. Of course, this is in Georgia and was a few years ago. This replacement came complete with fluid and torque-converter. It now has over 150k trouble free miles on it. Except for shipping costs, you would think something similar would be available there.
Good luck!