I own a logitech marble trackball mouse. It's more efficient for me and I've used trackball often and enjoy them. The problem is, I do not have a MMB. Therefore, ALT+MMB to pan will not work. I really wish there were other shortcuts or a free camera.
there is alternative way:ALT + SHIFT + LMB
unfortunately I can't offer a way to customize this because the alt, shift, ctrl keys are used for the tools as well. So I hope this works for you.