Has anyone done a Python CLI to edit Firefox bookmarks ?
My worldview is that of Unix file trees; I want

find /re/ in given or all fields in given or all subtrees
cd
ls with context
mv this ../there/

Whether it uses bookamrks.html or places.sqlite is secondary -- whatever's easier.
Clarification added: I'd be happy to quit Firefox, edit bookmarks in the CLI, import the new database in Firefox.
In otherwords, database locking is a moot point; first let's see code for a rough cut CLI.
(Why a text CLI and not a GUI ?
CLIs are simpler (for me), and one could easily program e.g.
mv old-bookmarks to 2009/same-structure/.
Nonetheless links to a really good bookmarker GUI, for Firefox or anything else, would be useful too.)
I don't know about all the features you've mentioned but "Organize bookmars" option in the Bookmarks menu is pretty decent with respect to features.
Python CLI to edit Firefox bookmarks?