i would consider moving the buttons that you have above and below the trackball, as it is pretty easy to hit them in a game of golden tee. i would just move them up beside the start and coin buttons.
another thing that you could do is wire the mouse buttons up to 2 of player 1's buttons. this gets rid of two buttons on your panel and works fine in mame. the only problem with this is if you also want to emulate something like the snes, since some non-mame emulators dont allow a mouse button to function as a game button.