Okay, we did all that and this is what we found: after checking the relays, one at a time, the only time the #8 fuse blows is when the #27 (starter relay) is installed. When we removed the bottom cover of the fuse box to check the wires, there was no corrosion at all inside the box.
We took note of the starter relay wiring with the relay out: the red wire has power all the time (with the key off, on & at start), the dark brown wire never has power, the yellow wire has power at start only, and the tan wire never has power. The starter motor solenoid trigger wire is also dark brown, and with that wire removed from the starter solenoid, the fuse still pops.
Two other things, the starter relay is new, and when we turn the key to the on position, we can hear the fuel pump running.