Yes, the operator presence control (safety switch) is located in the right-hand control lever. This was done to prevent the engine from cutting in and out when mowing on rough terrain, and to provide the operator more freedom to shift their feet and weight without killing the engine. It was also done to allow the GrandStand to be run in a walk-behind mode. If you let go of the handle the blades are de-activated, but the engine continues running, allowing the operator to easily dismount and re-mount the mower without having to go through the wasted effort of setting the brake or re-starting the engine.
As for the OCDC, it is part of rubber discharge chute (mounted to underside of chute)and therefore doesn't add any extra width to the deck. It is also made of the same rubber material as the chute, so it is flexible / pliable.
-The Toro Company