I just tried to disable the integrated intel hd and it causes Playonline to crash and when I disable it when the game is running it simply goes blank...
if i update it to windows 10 will that increase the odds of compatibility?
If you disabled the integrated gpu and it causes it to do something different then that means it was utilizing it. Fiddle with your settings until you get it to work like that, as it should remedy your issue.
As for the "compatibility" FFXI runs on directx9 emulation via directx11, once you disabled your intel card if fiddling with your nvidia's settings the only other thing to really do is change driver versions and see if it helps.
There's a way to bypass all of these issues but it basically requires running a VM. (To be fair, I've never logged my fps in my vms, but they seem decently smooth).