Now Chris play nice with the noobs.

Robotron uses two 8-way joysticks. The left one for movement and the right one for fire.
Your spinner and trackball will not conflict with each other unless you move both at the same time. Windows doesn't make a distinction as to which mouse is doing what. For example let's say your spinner is connected to the x-axis on the Opti-pac and your trackball is connected to the x and y axis. Now move your spinner in one direction and the trackball in the other direction on the x-axis. Windows will move the cursor in the direction that is rotating faster. This would even happen if the two devices are connected to separate Opti-pac boards.
As far as the buttons go you can map MAME to recognize any button to perform a particular task. If you want to use player one buttons in conjunction with the spinner and or trackball that is perfectly fine.
TTFN

Kaytrim