And finally the resolution. I replaced the two transmission mount bushings, the rear differential mount bushing and the guibo (again). But the root cause was the failed (frozen) u-joint in the driveshaft. It was only moving freely on one axis. The other was nearly impossible to move. Now what probably led to it's failure was the combination of all of the other worn out parts in the system. That and not replacing the guibo and center support bearing together on the previous attempts. All of which led to the pin bearings in one of the cups deteriorating and jamming themselves into an angled position.
I was able to get a rebuilt one from Wholesale Import Parts for about $450 including the core charge. Not the cheapest out there, by far not the most expensive out there, but nice people and quick service.
Thanks to everyone above for the input and suggestions.