Thanks everybody for your contributions. This is the list of things "discovered" and corrected so far and those still puzzling:
1. Fuel injectors removed and cleaned 3x by me and then professionally cleaned. There were some problems here but I no longer believe fuel is an issue.
2. I noticed 4 of the timing ribs (not sure this is the best description of them) on lower flywheel or stator had some rust coating so I wire brushed them and painted them and then readjusted the stator (flywheel) sensor. This showed a remarkable improvement in the backfiring problem and fixed fuel bleed line leeks and ruptures, but still power on all cylinders came and went seemingly mindlessly and mostly only a few fired at a time.
3. Top starboard spark plug clip had recessed away from the spark cap so may have caused sporadic missing. Rectified.
4. Battery Positive Post butterfly screw while tight to the feel was not properly securing the leads which could be moved by hand. This obviously accounted for occasions with dead starter conditions. Rectified.
5. I read a post from Faztbullet (December, 2012) to somebody else's problems that the shift interrupter switch on the shift bracket kills cylinders 2, 4 & 6 (all my cool port side cylinders!) so I isolated the switch but still suffered uneven running (the switch still made a very slight difference even with the uneven running). With the switch isolated and motor idling (poorly), disconnected all the power plugs to the port side coils (CDMs) without discernible change in engine performance & then started doing the same on starboard side with engine dying after two disconnected. Moved all port side CDMs to starboard and vice versa, with identical outcomes to the above. So it seems there is not a coil problem, but port side pistons are not really firing consistently and at times, not at all. Yet on some earlier occasions (months ago) all pistons would fire fine at cruise speeds for probably 3-5 minutes and then the problems would manifest. I have not yet tried Magnum19s solution above regarding a dropped exhaust tuner, but could this be having such a dramatic affect on the port pistons, assuming starboard are still doing their job? I will be immensely indebted for the answer to this problem! Thanks.