I like to use ESDF rather than WASD.
When attempting to bind the camera panning controls, I found it impossible to bind "Pan Right" to F; this made sense, since there's a conflict with the "Fill" button. So after rebinding Fill to "A" (which is now free, since I rebound "Pan Left" to "S"), I tried again to bind "Pan Right" to "F"; I still can't do so, even though nothing is bound to "F".
Interestingly, I can bind "F" to any of the other "Pan" buttons..