mentaltyranny

I finally figured out the issue.  It somehow the player gets "stuck" in the Kyne's Peace faction, whether through the animal allegiance shout, Kynarth's blessing, or otherwise.  You can see if the below fix will work by opening the console in 3rd person view, clicking your player character, and typing the following: 
 
getfactionrank e0d58 If the console reports a value greater than or equal to 0, type the following in the console: setfactionrank e0d58 -1

I finally figured out the issue.  It somehow the player gets "stuck" in the Kyne's Peace faction, whether through the animal allegiance shout, Kynarth's blessing, or otherwise.  You can see if the below fix will work by opening the console in 3rd person view, clicking your player character, and typing the following: 
 
getfactionrank e0d58 If the console reports a value greater than or equal to 0, type the following in the console: setfactionrank e0d58 -1

Okay, I finally removed the cart flipping with gsync ENABLED and using SLI.  I followed the post here, with the exception of, instead of 85, setting the FPS cap to 58.7 in nvidia inspector (which what I think he meant to say and just typed it in reverse as "set fps cap to 85") and ignoring setting -iFPSClamp=0 (iFPSClamp is not in my INIs anywhere at any setting, and looks like that is the default according to the INI guide wiki anyway).  Frame rate does go a little above 58, but never over 60.  Wild cart rides are no more!
 
As for the z-fighting and pixilated shadows, I am going to use bethINI.  However, considering that it makes INI edits based on mod configuration, I am not sure where in the STEP Core & Extended process to run bethINI... now? After completing STEP? Between 2 steps in the mod installation process somewhere? Any help, as always, is much appreciated.