I see you're spending a fair amount of time with the ignition system, but wanted to share what my experience was when I suffered thru the same symptoms years ago.
Found a faulty crankshaft sensor, after my local dealer couldn't seem to find the problem. They kept the car for almost a week, and kept thinking it was the ECM, but could not get it to fail. That was my wake-up call, telling me that the average mechanic dod not knwo what they were working on, regarding these cars.
The coils and all that are not going to know when to fire if they don't get the signal from the crank sensor telling them when to. I don't know if you've checked/changed the crank sensor, when you say a "variety of sensors".
All I know is, it solved my problem. Might be worth a try on yours if you haven't changed it yet. Good Luck!!!