With all due respect, you are long on criticism and short on
suggestions.

I'll be happy if I can:

1. Locate the cause or causes of the neutral wire to green wire low
resistance.
From what information have you posted that any of us could begin to
post helpful information on this ?


2. Eliminate the apparent neutral wire leakage/imbalance (hopefully as
a side benefit of #1).

I am not convinced there is an inbalance based on the readings from a
$50 radio shack ammeter, that is subject to picking up magnetic fields
from adjacent wires that are not passing inside the clamp. What did
you read exactly? Did it change as you changed the position of the
ammeter (e.g. rotate 45, then 90 degrees) ?

3. Understand the overall AC wiring scheme including the locations of
the neutral bus and green wire bus and how they relate to the wire
coding scheme.

From what information ?

4. Get the green wire bus properly grounded.

From what information ?

5. Install working GFIs where needed (galley and heads).

This is extremely easy,

6. Verify that all loads and branch circuits are properly connected.

Any other suggestions?