Mouse Configuration/Problem

How do I configure my mouse keys? I would like to change the CTRL-MOUSE RIGHT KEY, command from rotate the viewport to another more usefull. I am also facing a problem with the SHIFT - MOUSE RIGHT KEY command, when I am not drawing and press this key combination I get the POP 0 menu with the SNAP options, but when I am drawing and need to snap to some object and press this key combination I get the ORTHO toggle! Seems that the SHIFT key ignores the CTRL key.How to fix this?Marcelo