Well...FYI... I sorted it all out. :-)
The flickering was due to the fact that the battery shut off (in post #2) was in the off position. So when I got my unit back from the shop apparently they flipped the battery shut off bypass. After flipping all my breakers and checking all my fuses is when I found the battery shut-off knob (post #2). Once I flipped that to ON and turned on all my breakers.... ALL was good.
FYI: also to note was that my Dometic Fridge was reporting E0. Apparently, the fridge defaults to a E0 error at very low voltage (i.e. because of the battery override shutoff). Anyway, the ONLY way I could get the E0 error to go away was to access the back of the refrigerator (from outside the RV) and physically disconnect the 12V DC wire. Once I disconnected the wire.. waited 5 min.. then reconnected, the error went away. No combination of flipping breakers did anything.. only disconnecting the wire..
I hope this can help some one in the future as it took me HOURS to diagnose. :-)