I think I found a solution using a few other plugins. Basically, I setup a preconfigured sample site, disable the menu item for GeneratePress, and use the sample site as the default template for new users. This only works because A) there are no users yet, and B) I plan to use GeneratePress child theme to create variations from which users can select as their theme. This is along the line of my original plans anyway, so it doesn’t create any extra work for me. As super-admin, I will still have access to the Hooks plugin, which I’m sure will be a very useful tool.
I gotta say, I am so glad I found GeneratePress and the accompanying Customizer plugins. It’s like your read my mind as you were developing these and delivered what I needed. Thanks! π