Yeah, not going to argue that crappy fluid causes a lot of issues - for the most part, most trans fluids are actually hydraulic fluids, and some have friction modifiers, but for the most part are poor lubricants. I've added a qt of 30W non-detergent to most of my builds for about 20 years to help lube the planetaries, bushings, etc. Some may dis-agree with this practice, but it has never caused an issue for us, and inspections of transmissions that we have used the oil in always show perfect wear items. As to the intermediate shaft, I'm pretty sure it was a re-builders tip, but starting about '92 or so we usually drilled out stock shafts (PITA) until the upgraded ones came available. Once we started using the modified intermediate shafts and the qt of oil, we did 100+ units with pretty much nil comebacks.

Kinda funny that it took the factory from '88 to '98 to fix the issue by changing the fluid - sharp re-builders had cured the problem long before.