How is rotor pitch best managed in helicopter autorotation?
No, that is not how it is done: minimal collective blade pitch is not negative. The procedure is to lower collective immediately to the full down stop to minimise blade drag, upon which the helicopter will start to descend. The air upflow tilts the local lift vector forwards. Indeed, just like in a glider.

The bit that is not intuitively clear for fixed wingers is the reference frame of the airflow, which is the local blade velocity.

The inner bit of the rotor blade has a lower rotational speed than the tip. The up flow has a relatively larger influence on the lift vector tilt here, and  upflow through the rotor drives the inner part of the rotor blade forward, while the outer part still experiences decelerating torques. From Leishman: