CiviMail not sending mails in 4.7.6 / Drupal 7 "DB Error: syntax error"
If you'll notice (as per your Google Doc you posted), the last VALUE that the query is trying to insert is ( 1668, , 3537, null, '78ed5224ae6ab7d9' ).  The second argument is missing, and therefore the Query is invalid.

Double check if Contact with ID 3537 has an email address associated with it.  I don't know why Civi wouldn't catch this error, but that seems to be the issue.