OK guys, first of all I'd like to thank all of you for taking the time to look at the photos and post your observations and comments. I'll now attempt to answer your questions and provide clarification...
The original panel WAS inspected by the city 17 years ago when the house was built. The "Passed" sticker is still on the inner side of the cover door.
There IS some sort of platic lip/ring around the main service entry KO (where the fiberglass insulation is). Those wires go right into the meter box on the other side of the garage wall.
The lower bare CU wire from the main panel goes down inside to wall, then exits on the outside of the wall and goes into the ground. I assume there's a grounding rod down there somewhere. The upper bare CU wire goes up into the garage attic, across the joists and down the main house's wall into the basement where it connects to the main water line.
Both panels are Siemens, and neither of the panel information labels mention anything about using anti-oxidant compound.
The paper (warranty info card) has been removed. I did use wire to secure the cables but I thought it was OK since that is what was used in the old "inspected" panel. I'll remove the wire and use zip ties if that's a listed method. The circuit identifying labels are already on the panel covers.
The 100A feed uses three #2 wires and a #4 (all black). The #2 neutral is reidentified with white spiral tape. The #4 is reidentified with green spiral tape. One of the #2 hots has a single small piece of red tape at each end just to make it easier for me to know which wire to tug on when I was adjusting the length of the wire runs. Both the green and white reidentified wires of the main feed are connected to the main panel's grd/neu bar right next to the 100A c/b.
In the sub-panel, the #2 white spiral neutral goes to the neutral lug on the upper right neutral bar. The neutral tie bar was left in place connecting both neutral bars. The green bonding screw next to the neutral lug was completely removed so the neutral bars are isolated from the panel's case. The #4 green spiral ground goes to the upper end of the grounding bar on the left side of the sub-panel.
Reidentifying the #2 neutral and #4 ground shouldn't be a problem since they're #4 or bigger. For the 220V 50A circuit, I used 6-2 romex with a bare ground. The wires in that cable are black and white. Is it a problem that I reidentified the white wire to be spiral red?
For the 220V 30A circuit, 10-3 romex with ground was used with red, black and white wires, so there's no problem there.
Paul