The nosegear does have a single lockout debooster valve like each main gear brake has in order to deboost hydraulic pressure, provide leak protection and fluid quantity adjustment on the low pressure side of the valve as the brakes wear. Below that valve on the nosegear is the replenishing switch used to operate a solenoid to pressurize the nosebrakes for ground inspection and sevicing(with 'A' system hydraulics available).
Exactly.
Concerning activation of NLG. As a former FE I had to check the NLG with the replenishing switch and A pressurized in the morning. So someone in the cockpit had to push the pedals. ALL stated afterwards that they had to push it almost to the mechanical limit to activate the brakes.