Et said:
"The magnetic field of the Earth has it's source in the liquid Iron outer core of the Earth. The Van Allen belts are NOT stable on their own and require the geocentric magnetic field to exist. The ISS routinely travels near the VA belts at high latitude and magnetic field intensity is not what one would expect if they were the source of the entire geomagnetic field."

I have heard that story before but I do not believe it. First of all, liquid iron can not be magnetic, if any ferromagnetic material is heated sufficiently it will lose its ability to display ferromagnetic effect.
The only way a hot and conductive material can create a magnetic field is if it is conducting an electrical current through it, or if it is ionized and moving at high velocity.
Certainly the liquid iron can have ions associated with it, but where would the EMF come from that would generate enough current density around the iron core of the Earth to generate the measured magnetic field?
I do not think that it can happen the way it is explained.

The idea of the ions that are orbiting around the Earth (in the Van Allen belts) causes the magnetic field, sounds much more plausible.
After all, the ions in the Van Allen belts have been detected with instruments, the motion of the Earth's iron core has not been detected. The ions in the Van Allen belts have high velocities, the motion of the iron core can not be very high. If we cause electrons or ions to move in a circular path, such as in a solenoid, there will be a magnetic field within that loop, similarly the Van Allen belts form a loop of moving charges around the Earth, thereby creating a magnetic field within the loop and around the Earth.

Why would the Van Allen belts NOT be stable on their own? The jet streams are in a much lower and more turbulent area of the atmosphere and they are relatively stable from day to day.

The ISS and the trips there and back could be used to determine whether the magnetic field originates outside or inside the Earth.
If the magnetic field originates within the Earth, then according to the laws governing the magnetic field strength and its decrease with distance, the field strength should be measurably weaker at the distance of the ISS, if the field originates with/in the V A belts then the field strength should be about the same on the surface of Earth as it is at the distance of the ISS.
If such measurements have been made, then I would like to see the results.

Thanks for the input.
Ill tackle the other points in the future if/when I get the time.

Johannes