Proper way to ground a metal build and sub panel?

[Blue74]

Calling FredK and mgrist and anyone else with knowledge.

I'm getting ready to pull the wire through the conduit so I can depower and remove the overhead feed for the garages. I will be running 4 8ga wires for two 30 amp circuits. Two black, one white and one green. It will be feeding from a Cutoff Box that has two 30 amp fuses.

I have is I driven two 8' half inch ground rods, 8 feet apart into the ground next to the building. I purchased clamps and 50' of 8 ga bare copper wire for the grounds. I planned to run them from the ground bar in the breaker box I mounted to one of the frame members of the garage.

One thing I'm still contemplating is whether to run PVC conduit and pull wires for plugs and lights in the garage or use Armored Cable. I'm throwing that out there because I think it might affect other parts of this.

So the question is do I attach clips from the bare ground wire to the building between the box and ground rods OR should I use 8 ga insulated wire to connect the box to the rods? My concern is if there a short and the ground becomes energized will it make the building dangerous/electrified?

Also I think that the Cutoff Box on the house the ground and neutral wires are bonded BUT in the Breaker Box in the garage they should NOT be bonded. Do I have that right? I looked at the Breaker Box I have in the garage and I don't see a way to not have the ground and neutral wire connected unless I use the tapped hole to attach the ground wire. The photo of the Small breaker Box is from when I had it wired in the shed in Phoenix.

Thanks for the help in advance. I wanting the to be done correctly and safely. The mess that was in both garages needs to be fixed.