If I were to take a guess between the two, I would have to go with #1 which could be caused by #3. This could be resolved by replaceing the TC. That is unless you also have a leak in the TCC circuit of the valve body, which is very common so you might as well replace the TC and Valve body at the sametime. There have been people here that have done it themselves for around $500.
The truth is that I already have repalced the VB, TC and solenoid. At the beginning, TCC started to slip beyond 80MPH or climbing grade, if I drive below than that, it works fine. I first replaced the VB, no any improvement. Then I replaced the TC, problem becomes worse, TCC start slipping beyond 50MPH. Then I replaced the solenoid. No any help.
Now I am thinking probably it is the oil pump because the line presuure is in the low side. My next project is to replace the pump. I really don't have the confidence to rebuild the tranny. If the pump cannot cure it, I will quit forever. I really hate CD4E now. Why Ford design such a trash? The stupid engineers even design a filter inside tranny.
