No, I don't know exactly when the crash started. But I started really noticing it by Tsukuyomi's patch. I don't recall when that was, but I can check it out.

Yes, as long as I can alt+tab or get to somewhere stressed enough, such as a highly-populated zone in Hydatos.

No, it's not. I don't usually modify my GPU clock so there's that. I tried underclocking it due to a suggestion from another player, but no results.