Comment by Izkata

You're almost there. To get what I and others have, take everything you described then add:

* Ability to unload tabs and prevent tabs from unloading, by domain (youtube) or picking from the context menu for one-offs. (Auto Tab Discard) (Unless it's changed since I got this addon, the built-in discarded tabs won't unload tabs, it only does anything when the browser is restarted, preventing all but the current tabs from loading)

* The left sidebar is actually a tree, where links opened in a new tab are automatically children of the tab they opened from. The whole thing becomes self-organizing with context, and the parent tabs can be expanded/collapsed. (Tree Style Tab)

* The left sidebar also auto-collapses to ~3 favicons in width (userChrome.css manual modification, originally copied from something shared online), so it works fine even without a wider screen.

* Addon for vim-style controls (Tridactyl), which in addition to everything else includes a way to search and jump to tabs by matching title and url.

I'm somewhere around 1500-2000 and it has replaced my bookmarks.