Records

If this information is contained on a shop traveler that reflects the activities / planned arrangements performed, operator buy-offs and inspection acceptance of outputs to established criteria, does this shop traveler become a record that needs to be maintained? 

As you mention, the shop traveler can be kept as a record, since the standard ISO 9001:2015 requires to register the information about the activities and planned arrangements but doesn not say anything about how to do it, so you can decide about how to record this information.

Can a Certificate Of Conformance alone signed / stamped by inspection suffice as an acceptance of product compliance / Record of Conformity of Product (8.6)? 

Yes, however you will need to review the requirements of the product before it is delivered and keep this Conformace evaluation record in order to comply with the requirements of ISO 9001:2015.

Can a business elect to not maintain  completed shop travelers reflecting completion of planned activities and not be concerned about a 3rd party auditor wanting to view them, as long as they are able to provide visibility / outline of what the planned activities consisted of and the signed COC?

If the company chooses to use the shop travellers to reflect the activities /planned arrangements performed the third party auditor an ask to view them in order to comply with the requirements of the standard.

For more information about how to control documents and records in ISO 9001:2015, see the following materials: 

- New approach to document and record control in ISO 9001:2015 - https://advisera.com/9001academy/blog/2015/06/30/new-approach-to-document-and-record-control-in-iso-90012015/
- Enroll for free course - ISO 9001:2015 Foundations Course - https://advisera.com/training/iso-9001-foundations-course/
- Book - Discover ISO 9001:2015 Through Practical Examples - https://advisera.com/books/discover-iso-9001-2015-through-practical-examples/