Interesting. Not sure if this has solved anything (as I have had days where I can play with no issue) but I updated my graphics drivers to the latest beta versions and It's been ok for hours today but I just right now tried to teleport to Gridania and I got a crash, but not a system crash, a Visual C++ runtime error. Not sure if unrelated or because I changed my drivers but thought I'd mention it. I will be monitoring the game over the next few days as I fully expect the system crashes to come back but if by some miracle they are gone (or replaced with this runtime error) then it's a step in the right direction.