I disagree, and here's why: I can do the same thing with normal mice. I position four trackball mice at very center of my screen, then I set the cameras to the same viewpoint (Blizz provides a keybinding to do this for me), and then whenever I want to cast a targetted aoe the I hit the spell and then press all of the mouse buttons. It's a little slow, but I don't play aoe classes normally.

Now let's assume that I used the same hardware replicator that I use for my keyboards (Vetra USB 4-way broadcaster) on my mouse in order to press the button 4 times at once (still positioning them by hand before). Now I'll shrink-ray my mouse and duct-tape it onto my keyboard. Now I have a button on my keyboard that sends a mouse click to the center of my screen.

Granted, if there's a tree in the way of the camera, or I'm on a hill, or etc, etc., there will be problems. BUT, the same thing happens with the software solution. We're relying on the assumption that the camera is static in order to place our aoe. All AHK is doing is emulating the hardware I described. No sleeps, no information taken from the game, and there's one action taken with one button press. That sounds clean to me.