are macro's allowed in SC tournaments?
Not at all.
You don't have to use macros to use the keys on the Naga. All it's use for is so that your main thumb controls the 8,9,0 hotkeys instead or using your left hand and having to reach all the way to the right to use them. This gives you much more quicker control when playing. I use 1-4 for units, 4,5,6 for 3 observers or observers and prisms, 7 (on naga mouse) for single or groups of workers, and 8,9,0 on the mouse for buildings.
No macros used, just less left hand movement and quicker control groups control.