If one adds pure torque to a disc rotating about a fixed axis in such a way that the application of the torque is off the axis of rotation with the torque vector parallel to the axis of rotation, does the added torque provide angular acceleration to the disc's rotation about the fixed axis regardless of point of application? By pure torque I mean a couple with which no net force is exert on the disc. For example, if a rotating disc had a magnetic dipole attached to its outer edge with the magnetic moment facing the direction of rotation and then a uniform magnetic field was applied to the system such that the dipole's moment were not aligned with the applied field, at that moment in time a torque would be applied to the disc at the point where the dipole was attached.
No, because you cannot add torque, you can just add a force. And then the torque generated depends on the point of application:
$$ T=F·r $$ (A vector product)
If you could add pure torque it wouldn't depend on the point of application. But you add a force and then a torque appears.
A pure torque does not have a location where it is applied. It is felt uniformly by the entire rigid body. As a result, the body is going to rotate about the center of mass. If there are is zero net force, then the center of mass will continue moving with constant velocity (or be at rest).
The equations of motion state that net force affects the motion of the center of mass only, and net torque the motion (rotation) about the center of mass. This is a direct result of the definitions of momentum an angular momentum, and Newton's 2nd law of motion.