Sat Jun 20, 2015 8:39 am by lax
As far as ffxiv_dx11.exe itself, this new exe is not recognized as FFXIV by Inner Space at the moment and so mouse control is broken in DX11 mode. A fix for that will be coming shortly.
As far as the crash I would try shutting down other running programs to see if the behavior stops. I assume your video drivers are up to date via the GeForce Experience program, so I won't tell you to update them. But if there are any application-specific settings selected for ffxiv_dx11 in your nvidia settings, that could be related to the problem.