I have the latest Logitech key board where F11 & F12 are for my sound adjustments, anyone know how I can access GSX by keyboard!
This depends if that logitech utility has stolen the F12 keys entirely, or it still allows you to use it for something else when in combination with CTRL+Shift, which is what is required by GSX.
If the key has been stolen entirely by that utility, the solutions are the same whenever you have a key conflict between two apps:
1) Don't use the app that cause the conflict, in this case the Logitech utility
OR
2) Change the keys used by the Logitech utility. I don't know if this is possible.
OR
3) Change the keys used by GSX. This is of course possible, from the Couatl menu. Of course, you must be sure you are not assigning GSX to something that has been already taken by something else.