Just incase anyone else has run across this, because I did a bunch of searches and found nothing. If you run EVGA Precision (it's an overclocking/fan regulator program for those unfamiliar) and your FF14 game crashes immediately on launch after installing, uninstall Precision from your system, reboot, and reinstall directx. Apparently that program messes with some DLL file involved in DX9 games. Hope this saves someone else some time.
XI Wiki

