You’re right, the blades are essentially ‘gliding’ in their plane of rotation, which takes constant adjustment of the cyclic pitch, note that’s only valid for forward a flight path and not intuitively obvious. If you were to land at this constant velocity, you’ll spread the skids (at least).

Before landing, flare to increase blade speed and slow forward motion, increase the collective, arresting your descent at a moment before meeting the ground, but there’s only one chance.

Ehh, the blades don’t “reverse pitch to negative”. That would send you plummeting to the ground. The range of pitch of the blades are no different when your autorotating than when you are flying normally. You simply adjust the collective (blade pitch) to regulate your decent just like you would if they were being powered. The only difference is the air coming up through the blades from your decent keeps them going instead of the engine. If you arrest the decent, the rotor speed will drop….and so will you.

Its not automatic, but a pilot can do it. You reverse the pitch of the blades to negative pitch so falling through the air spins your unpowered blades faster. Then you take that stored up kinetic energy in the blade speed and reverse the pitch so it stops your descent right above the ground. A skilled RC pilot can do this with a model as well.

-_o