3. Fuel - Fuel spar valve. I thought I read somewhere that certain designs also pull a valve in the HMU. Would this be the same HP SOV as is controlled by the fuel lever in cockpit for normal start/stop?
Not all are the same but yes some/most will shut off at the SPAR and the HP SOV
4. Hydraulic - this one got me. In case of an Engine Driven Pump, would it be physical disconnection from the gearbox?
Most Boeings just cut the supply off so the pump still has fluid in it but will require overhaul due to overheating.