Scott,
As always thank you for the detailed post and for taking the time to give me some direction. I'm at the coach tomorrow and will test all the things you suggested. I was aware from the '21 responses that the hazard activity was normal, but didn't notice the turn signal issue until last week for whatever reason.
The coach has an additional brake controller; It also has the tow different two wiring setups I put in the BAC post.
Yes, the four red in the tail light stacks, the two amber, and the center LED (of which half are burned out and I can't find a replacement of the same size) all flash with the hazards on. The coach also has aftermarket headlights which I have been meaning to change, but the right light seems like a PITA to remove with the air horns in the way, as it looks like I need to remove the brackets from the inside to get the lights out. I'll check and see if they blink differently.
Will report back tomorrow. Thanks again.
Anand