https://addons.mozilla.org/en-US/firefox/addon/edit-bookmark... covers that use case.

I think the bookmark overlay has not received updates in a long time. If you use it often with many tabs, it's actually quite a pain to use it.

Except for the bookmarks window. Can you elaborate?

Since the days Firefox 3 it is no longer possible to resize the bookmarks window you get when you press Ctrl+D or click star.

The solution was to hack userchrome.css or install OpenBook add on.

However it is no longer being kept up to date with Firefox.

A possible update for it is to use Edit Bookmark Plus instead.

Some information here, https://bugzilla.mozilla.org/show_bug.cgi?id=418864

Calling that the "bookmarks window" will just confuse people. It's not a window.

A GUI widget then.