Here are my $.02 on admin buttons. I think an Exit button is necessary, as well as a pause button. there are no need for menu and enter buttons. i run MaLa on both of my cabinets. i have mala set to launch the game when i press the p1 start button. in mame, player1 button 1 doubles as Enter. when you say Menu button, is that for the MaLa menu, or the mame "tab" menu? either way, dedicated buttons are a waste. in mala, i either use the p2 start button, or the exit button to bring up the mala menu. in mame, i use a shifted commands to bring up the tab menu (to keep people from doing it accidentally, nobody needs in there but me). i like having a dedicated pause button, it is very handy. i really like having a dedicated exit button as well, however there can be problems with it. on my old 2 player cabinet, i had the exit button at the back left corner of the panel, so as long as i was player 1, nobody could reach it....this works very well. however on my new 4player showcase, i put the exit button at the center of the panel, along the back edge. this works well for symetry, however my 20month old son loves to press it....either while sitting at the barstool with me, or he walks around the back and reaches up and hits it. (i made the mistake of using a light up red button for exit, so naturally he is drawn to the one button that lights up)
i have been looking into an AHK script to make it so that you have to hold the button for 2 seconds to get it to exit, but that seems to only work with older versions of mame (im using .124). i did not originally include a pause button on this panel, but i ended up mapping my exit button as pause, and you have to press pause + p1 start at the same time to exit. it is'nt quite as obvious to guests, but it keeps accidental exits from happening