Is the transmission, input shaft or anything actually engaged/spinning in the gear box if you're at a stand still in neutral, clutch pedal off the floor?

 

Disregard. After thinking about it, the input shaft would spin since the clutch is on the flywheel when the clutch pedal is off the floor. Everything would spin besides the output shaft until in gear.

correct me if I'm wrong.

 

if the car is on a lift or jack stands you'll typically see the wheels spin slowly because of the viscosity of the fluids in the transmission, but you'd be able to touch any wheel and stop them with little to no effort

and yes, input side would all be spinning, output side would, for all intents and purposes, not be spinning

 

Certain gears on the output shaft would be spinning, but not the shaft itself- 1, 2, 5, and R will be spinning on the shaft with the shaft not spinning, and the reverse idler would be spinning. 3 and 4 on the input shaft would not be spinning, and the input shaft would be spinning inside of them. This is because the 1-2 and 5-r synchro hubs are on the output shaft, and the 3-4 synchro hub is on the input shaft. Gears 1, 2, 5, and R are a part of or splined to the input shaft, so they spin with it. The gears on the synchro hubs are able to spin independently of the shaft they are on, because they need to be able to that for the trans to work.