Header Tools; insert options.
 

In the page setup settings, I have the three panels, left, center, right. Then I have a pull-down option to "insert" a bunch of preset text; date, file name, etc... Is it possible to add custom stuff to this insert list? For example, my address, office hours, etc? etc...

You can type anything you'd like directly into the fields. The list contains variables and not static values. We have thought about having some customizations of them but I'm not sure where we'd pull something like your office hours from.