Hmm, the Toolbar and Menu have always been distinct categories. I don't recall when Unsorted Bookmarks came along, probably in Firefox 4.

It sounds as though you are going to end up with a lot of duplicates if you are maintaining complete sets on both the Toolbar and the Menu. Do really need to use both?

There are a lot of bookmark related extensions on the Add-ons site, but I don't have any particular recommendations. It sounds as though a global bookmarks search box might be a good start so you don't have to check multiple folders.

You also can suggest features changes for future versions of Firefox here: https://input.mozilla.org/feedback

Unsorted Bookmarks has been around since Firefox 3.0, when the 'new' Places system for combined Bookmarks & History was introduced.

As far as duplicate bookmarks goes, Firefox 3.0 and later versions won't save a duplicate bookmark by clicking the Star button or via { Ctrl + D } - but the user may save a duplicate bookmark by doing a drag'n'drop to the Bookmarks Toolbar directly, by a drag'n'drop to the Bookmarks Sidebar or the Bookmarks Menu (when the Menu bar is showing and you hover over Bookmarks to open that menu), or a drag'n'drop to the dual "Star" / "Show your bookmarks" button on the Navigation Toolbar (hover the cursor over that dual button and the drop-down will open).

After some tinkering I found a way to accomplish what I want, and fortunately it can be done in the current Firefox application without need for an Add-on.

I simply copy the top-level Unsorted Bookmarks into the top-level Bookmarks Toolbar and into the top-level Bookmarks Menu. This, combined with the convention of adding all new bookmarks into the Unsorted Bookmarks or folders under Unsorted Bookmarks, provides the unified bookmark content I want across all 3 bookmark views (Unsorted, Menu, Toolbar).

From the Library page (brought up by selecting from the Firefox menu bar Bookmarks>Show All Bookmarks), if I select Unsorted Bookmarks, copy it, and paste into Bookmarks Toolbar and paste into Bookmarks Menu, this does what I want. I've effectively created a reference/symbolic link/shortcut to Unsorted Bookmarks from the other two places bookmarks can be found.

With Unsorted Bookmarks contained in Bookmarks Toolbars and Bookmarks Menu, any add/delete of bookmarks or add/delete of folders or restructuring of the directory tree for bookmarks under Unsorted Bookmarks is also immediately reflected within all 3 of the possible Bookmark locations (Unsorted, Toolbar, Menu).

The design and implementation of bookmarks supports this simple solution, so kudos to the designers and coders for the built-in extensibility/generality to support this approach. And thanks for the posters for giving me some context and history about bookmarking in Firefox, motivating me to dig in to find this solution which is quite elegant and simple.

Thanks!