You can change the default fonts your objects start with by going into:
C:\Program Files\Adobe\Acrobat 9.0\Designer 8.2\EN\Objects\[Barcode,Standard,Custom, Favorites]
Edit all the xfo files (they are just XML files). Change out the Myriad Pro for whatever you want. I had to change mine to Calibri for templates/PDFs we were doing at work.
Hope that helps anyone