There are the following apply methods of interest:
ApplyForce and ApplyTorque both need large values. The Impulse versions does only need low values for something to happen.
ApplyTorque() applies a force to the bodys angular velocity. It is basically calculated and applied like this:
deltaVelocity = torqueAmount * inverseMomentOfInertia * deltaTime
angularVelocity = previousAngularVelocity + deltaVelocity
ApplyAngularImpulse() applies its amount directly to the angular velocity. It is calculated like this:
angularVelocity = angularVelocity + torqueAmount * inverseMomentOfInertea
Basically impulse is assumed to include the dt (delta time), so when you apply an impulse of 10, it would be the same as if you apply 1 force over 10 time units. Hopes that makes sense.
They all works fine, are you sure you are drawing the textures correctly? The bodies might change position in the physics engine, but you might not be drawing them right to see the changes take effect.