Hey, you seem to be in a very similar situation to my own. I've tried almost every solution under the sun, including almost all of those you listed here, and the game still crashes on specific cutscenes, or during dungeons. Theres even zones i cannot enter or im gonna randomly crash at some point.

With the amount of forum posts regarding the crashing issues, I am now convinced the fault does not lie with us or our computers. It really is embarrassing for a game this popular to have such major and relatively widespread crashing issues...

I've enjoyed my time playing, but I see no reason to continue, especially since I literally cannot progress the MSQ due to a 100% crash.