Fried ECM
As if all these lead to ground.
Voltage exists when there is no current.
So the first two voltage measurements have nothing to do with grounds.
Whatever the battery positive is connected is at battery voltage.
Think of it this way. Turn off all the faucets in the house, there's still 60 psi or whatever your pump/city provides in the lines.
The mysteries are:
a) Why is there voltage at those test locations with the switch off? (that's what 67Dart273 stated above, just restating it here)
b) Why is there a voltage drop ignition wire.
Seeing 12 V on both sides of the Voltage regulator makes sense. When there is ony 12 Volts at the regulator, the upper points stay closed so maximum current can flow through the rotor.