No, the update did not fix the driver crashing and recovering. It is how I ended up on this page today, literally just hit back in my browser and it hung, then driver crash. It is very sporadic.
i7 256gb 8gb / dGPU
I've had this happen to me and once I disabled the camera from being an option on the lockscreen (in the form of a swipe) it never happened again. It was weird when it was doing it though.
Honestly, the only time my fan gets going is with firmware updates and if I'm watching movies for an extended period of time... I am in joy with my SP3
As for #2... You do know that it is possible to just project it to the second screen only (your external monitor) the SP3 screen will be off when this is selected