Single sprite with multiple collision zones

Just curious, is it possible to have a single sprite with multiple collision zones?

You can use dummy sprites set to select image points on the main image.

So..."stack" sprites, but where does the sprite stacking occur? In the animation editor or on the game layout?

You would do it via events. Like if dummy variable =1 set position to mainsprite image point("1")

As newt says, just use other invisible sprites and position them by the visible sprite. Then you can test for collisions with the invisible sprites.