Hi Eric,
I believe the default menu name would be "main". There is no UI yet for creating additional menues, unless you go to the Hippo Console (I'm not 100% sure how much of the old URL en Navigation Management functionality UI is still present and working in this respect).
So much about visibility of the menu. Editing is a funny thing. We've set up the default template to render a "Edit Menu" button, which, if you're in the Template Composer's Edit mode *and* your menu component is *not* inside a container, opens up the new 7.9 menu editing dialog. However, if your menu component is in a container, clicking the Edit Menu button will open the component parameter dialog, which takes precedence over the menu editing dialog. AFAIK, this is still a hick-up in the Template Composer that needs to be addressed.
cheers
Tobi