Well that's probably exactly my issue as you can see in my 5th step the oAuth credentials I'm using were the "create_customer" type.
Changing to full permissions scope got a user token returned to me which is what I've been needing...
Can I give you a big "THANK YOU!" for that nugget of wisdom. VERY useful!
As a side note, what is the "create_customer" scope for, if it is not, in fact, for creating customers?