many modern rpt jets have at least one wow per gear, some 2 sensors.
I am not licensed on any aircraft with assymetric spoilers for landing.
Once sensed, up the spoilers go.
mains are generally braked during the retract cycle, nose wheels have kevlar snubbers in wheel well.
gears pins used during many maint procedures mostly when towing.Procedures vary between companies and ports.Always used where stated in the manuals plus where company policy dictates.
Our company does not use the nlg lock pin during pushbacks just the steering bypass pin.
Dont know of any that do here in OZ.
Does not mean some companies do but I reckon your are asking for a NLG failed to retract upon selecting UP report!!
Forget the tyre pressure thing.
Off means simply that hyd pressure off the retract actuators via electric or mech means.Gears just hang in the uplocks.