Mark, thank you for your work on this. I posted about my experience on this thread on 5/5/19, and apparently the scammers continue.
I find this piano scam fascinating. The complexity of the scam itself is a form of artwork.
First he sets the tone that the piano was a favorite of his recently deceased wife and second, he pulls on the heartstrings of those who feel compassion for him that the sight of the piano will cause him more pain as he remembers her. Third, he introduces the idea of significant change - the move from his home in Georgia to Miami. Fourth, he introduces the transfer to another party (the truck driver). Fifth, he transitions to the role of supporting change agent willing and anxious to facilitate the introduction to the Moving Company.
One addition to your list above. The scammer was insistent that I not resell the piano I would soon receive for free, and made me reassure him that I was a genuine piano lover, not a mere flipper! So I was trying to prove my good character, when it should have been the other way around. They have indeed refined the scam to an art form.
One reason the scam succeeds is that when your mind is made up to buy a piano, you are thinking in terms of thousands of dollars. So paying a few hundred for delivery of a free piano doesn't seem outlandish, when you would otherwise balk at handing over such a sum to an unknown party.
I was lucky to have remembered seeing an identical Craigslist ad from another location a few months earlier, so when the scammer introduced the imaginary mover, I walked away from the transaction.