Stalled blades produce torque?
I believe that they do. In fact, more than un-stalled blades subject to the same power.
Driven, stalled blades produce more drag than driven, un-stalled blades.
It's the drag rather than the lift from the blades that imposes torque on the rotor mast, which in turn produces a reaction on the bearings, given that the angular momentum of the helicopter, and the air that flows over it is fixed.