Figured it out...maybe.
After replacing most electrical hardware, began looking into sensors.
Found some ideas looking at various threads and landed on some posts online concerning jeeps with similar problems.
Long story short...replaced the "Crankcase Position Sensor"
VERY EASY JOB!
Don't know what caused the fault, but no probs since october replacement.
Thanks to all suggestions...Hope this can help someone someday!

To recap...
96 f150 6 cyl suffering VERY intermittent complete stop engine failure...died at any given speed, or wouldn't start at all..without prediction.

 

Good you happened on the problem.
That sensor starts everything going in the system.
It is the reference the PCM uses to control everything else.
It's signal starts the fuel pump etc.
Quite important, if it dosn't work the rest of the workers don't know what to do.