turtlevette,
as to 2, your premise was that the viscous oil sheared straight off the shaft, before you changed your tune to not getting drawn into the clearances...just saying, and also you never backed the statement with anything before you changed it to "cavitation" in that thread.
The article is an advertorial, not an engineering journal. There is a difference in how information is purveyed in the two fields. Of all people, you should know that.
A thicker oil will have lower side leakage, which will draw less oil from the galleries, which will make it run warmer...pure and simple. Have explained the process ad nauseum for a decade...go and have a look at the how bearings work thread, and follow the charts.
As to number 1, I don't recall us ever "debating that", except for your thinner lubricant that behaves like a thick lubricant in every aspect except viscosity...again which you've never backed with anything.
If you have a dino oil that is shear prone, and a synth that isn't, then of course over the course of an OCI you will have a difference.
If the bearing needs an HTHS of 3, a lubricant with an HTHS of 2.6, synthetic or dino is not going to help.