Q: Why can't I Customise the Rendering Templates in Movie Studio 11 and 13?
Answer: The basic versions Movie Studio 11 and 13, do not allow customisation of templates.
If you want to customise your templates, change bit rates and frame sizes, you will need to upgrade to the full Sony Vegas Movie Studio HD Platinum 11, Movie Studio Platinum 12 or Movie Studio Platinum 13.
Once you are in the Platinum Version, you must also hit the little triangle next to each Master Option in the Render As window and select a sub-template to get the Customise button to activate in the Platinum versions of Sony Movie Studio.