Perhaps a better solution already exists for you, though it is a bit hidden. On the Metadata Template window, there is a 'Clear' button, which, by default, clears out all fields on the Template. However, if you hold down the Option or Shift key, this button will change to Options. Clicking on this will bring up a separate window with options for whether it should clear the Field or the Apply checkbox.
So lets say you always use the Caption and Copyright field but are mistakenly applying other fields with the template. Uncheck Caption and Copyright (for both Field and Apply), and then moving forward, you can click the clear button to leave those fields un-cleared while the other fields get cleared. This saves you from having to scan the entire template for fields that you have accidentally checked: You know that once you click 'Clear' it will clear out everything but the fields you have specified.
Does that help?
