I am trying things with the Visions theme...
There is a basic menu featured as part of the theme.

Using the supplied menu is enough for a small site.
If we are to build out the nav menu, say with new drop-down items, is it expected that we will manually edit the menu supplied with the theme or create a new one externally and replace the nav in the theme?
Which way will require least effort?

Thanks,
D.

The various features you see in the themes provided by CC are all made with RSD. If you need a large and complex menu, I'd use CC's Menu builder to create it, and then incorporate it into your RSD project.