This morning I recieved the 7200 replacement.
Connected it up and all else remaining the same - issues resolved!

With replacement amp:
1. No discharge sound on power off
2. No transformer hum sound

I will be calibrating sound and other characteristics this week (#3).

I did wish to convey my thanks to Ben B. He was pro-active, cared about my issues and provided excellent support. Looking forward to enjoying the amp.

Thanks Outlaw Audio!