Q2. Have I allocated the braided jack earth wire to the correct jack lug?
No, you have them reversed. (presuming the other end is soldered to the pot casing - I can't tell in the other photo)

Q3. When running the earth wire back to the bridge plate should it the exposed wire touch the copper foil?
As long as the bridge plate is making contact with both the wire and shielding tape, there should continuity. However, it doesn't take much tape to run from the cavity to where the bare ground wire will be located just be sure.