Canards not only help with avoiding stalls by acting as a lifting surface on the front of the aircraft but they also allow for greater and slower maneuverability.
Hi Dave, Canards help avoiding stalls mainly because of a low pressure vortex that flows over
the wing. this vortex lowers the pressure over the wing and delays the flow separation (stall) at high angles of attack. I also have this draw that perhaps could help. (excuse my poor english and translation).
Adavis, about your second question, the elevons can be used fixed, as elevators, or elevons... the best way to use them depends on the airplane selected and what kind of flying you want to
achieve.
Regards, Enrique