I've never been into the idea of dedicated mouse buttons on a CP. Seems like a waste of space to me and doesn't seem 'authentic'. I mapped the mouse buttons as my player 2 fire buttons and left it at that.
Similarly, my admin buttons are tiny ones from RShack and are hanging off the underside of my cp, up near the monitor. You can't see them and I like it that way. I don't need to see them, I know by 'feel' which button is which. I have 4 mounted but only 3 hooked up, they're: Esc, 5 and P (for exit, coin and pause)
Also, looking at your CP, your 7th button seems to be in an odd place underneath all the others. I think I'd accidentally hit it with my palm while utilizing the others. YMMV, I guess.