ailerons don't work by changing the AoA of the wing. The aileron is a trailing edge flap that is deflected. If you look at the lift plots for such devices, you'll see that they are effective in increasing lift coefficient all the way to stall, but that the AoA (measured by reference to the original chord line) for maximum lift is marginally reduced.
Not sure I follow this.
Angle of attack is defined as the angle between the relative wind and a line from leading edge to trailing edge. What else could it be? Ailerons and flaps move the trailing edge, so their
main function is to change the AoA of the wing section. They also increase camber, but that is incidental.
The stall AoA is a maximum lift AoA. You know it is a maximum because both reductions in AoA, and increases to AoA, lower the lift. Which implies that the the graph is pretty flat, ie effectiveness is pretty low. One side is stable, the other isn't.
I should make the usual caveat: even if the inner wings are stalled, the outer wings might not be, etc. I am talking abut stalled wingtips (which modern designs try to avoid). Perhaps you were talking about aileron effectiveness when only the inner section is stalled?