An unstable graphics card will indeed crash the game and your computer at random. I've experienced this before with my own graphics card (ATI R9 270x), which allows you to control it's power consumption by -20% to +20% and I had it set to a negative value, which occasionally led to the GPU not getting enough power to keep up resulting in random blue-screens and reboots. Having the power control set back to it's default 0 position resolved this.

My conclusion is that TESO doesn't like tempering with your graphics card performance in terms of overclocking and such.

Correction to OP I have to correct you on one thing MSI Afterburner is intended for MSI cards mainly, and it will work on most of their cards (some won't work). The program in theory should be able to handle cards of other manufacturers as well, but there's no guarantee to that.