Add placeholder text box

I want to add some text boxes to my master that can be edited in new slides. But the only text boxes that can be edited are the title and default text boxes. All other text I add is nailed down, like stationery.

How can I add preformated and prepositioned text to my master that can be edited on each new slide?

Also, how can I get rid of the default text boxes? If I delete them from the master they still show on new slides.

Using PP 2004 for Mac