RE: Tip Stall
Rudder use INSTEAD of ailerons is the way to help avoiding the tip-stall when needing to do a turn at low speed.
The ailerons at low speed can create adverse-yaw. (drag of the lowered aileron opposing the desired direction of the turn.) This effect can in some cases overpower full rudder being used to aid the turn. When that happens, the tip stall will be immediate and will always result in a spin. (sometimes flipping hte aircraft inverted for an inverted spin)
Low speed turning control... use the rudder. Using the ailerons at stall speed can cost you the airplane.