One way to get EZ to start up with basic formatting, or basic styles, enabled is to tell it to edit a file whose name has an extension that it recognizes. The extensions which will toggle formatted text mode are: .txt, .text, .ez, .EZ, .eZ, and .Ez.
If you do want to enable the EZ features such as format control and various fonts and sizes (i.e, to treat the file as a regular EZ file), you can do so by selecting the Enable Basic Styles option from the Special menu card. Note that once you have enabled the EZ styles for a file, EZ will from then on treat this file as a regular EZ file, not as a plain-text file, even if the file does not have an EZ recognized extension.
For more information about filename extensions and EZ, see the andrew help section entitled Filename Extensions and EZ.