Database Mirroring - Mixed SQL Server 2012 to SQL Server 2016 I am pretty sure what the answer is but I want to confirm this.
Is there a way to create mixed DB mirrors SQL Server 2012 to SQL Server 2016.
The short answer is that yes, you can Mirror up to a higher version, but you should really only do this if you're going to upgrade. 

Once you fail over, you can't fail back down to a lower version.