Ldg gear questions
Most of your questions have been answered however wheels spin is due to friction and reaction due to weight on the wheels (3rd law Newton). So the rotation stops due to lack of friction between the wheel and the airflow and no weight on wheels. Only a few seconds later than a light tap or auto application would suffice rather than a full blooded application reducing the brake disc life. ldg gear selector is selected off for depressurising up lines and in order to maintain fluid levels. In most aircraft it happens automatically when a complete retraction is sensed. I think a WOW switch in both main gears is for integrity of operation in case of a failure of a sensor.