FUJI E1 selector custom functions

Hi,

I read the whole manual and cannot figure this out. The selector has one MACRO selector assigned and three unassigned buttons, down, left and right. Is there any way I can assign some functions to those buttons just like you'd do to an Fn button?

one more question. Is the Q menu customizable? a bunch of stuff there that I don't need. I love how it shows all custom sets if you keep it pressed for more than a couple seconds.

Thanks in advance for your time