The letter from Ignatius in all likelihood is translated incorrectly. The 19th century bible scholar John Kitto translated part of the letter as the "Lord's 'Way'" not the "Lord's 'Day.'"
Thus it appears to be arguing to honor the Sabbath as the Lord would have done so. Not as the religious teachers of the day taught. I would say if anything the letter by Ignatius does not one way or another resolve the Sabbath issue.
(Also, I would remove any reference made to Barnabas. Most scholars I have read argue that a gnostic penned his writings)