Want to create a sidebar menu for global product categories.

I have researched for weeks and come up short on a sidebar "global product category list" menu option.

My goal is to create a fixed list: 10 parent categories, each with 10 child sub-categories. I would like the parent names to list in the side bar. Click one, and sub-cat-names list underneath (over to the right a bit, sliding remaining parent names down below).

I can create a fixed list in my store-template, to have that list duplicated for each new site, using new blog templates - correct?

If I need to update that list in the future, I can use Multisite Content Copier to push edits to all existing sites - correct?

I have installed Multisite User Management to assign roles to new users. Is there a setting called "manage_categories" I can turn off for site admins - where do I find this?

I think I will have to build this menu system myself. I can manage css and html - html in a sidebar "text" widget, and css in my custom.css file. I need help to find the code.

Thank You!