Won't go thru all of it. Comparing the safety of a DUI at 70 compared to someone going 170 in a car built for it who isn't drunk or on drugs is absurd. Braking distance is irrelevant to drunkenness or being stoned.
The shimmy would likely go away at 170. The car has independent brake systems (not mentioned in the article) and that can cause a "shimmy" at lower speeds as there are dual ABS systems. I've never slammed on the brakes at 70 or 170, though.
It would appear your reasoning is that the speed limit should be based upon the fastest any car on the road can travel with perfect safety. So then what? 30? 35?
What do you think is the fastest speed everyone can safely ride a bicycle and how low a speed limit should be on that?