Seconded. Firefox is better than ever. Can't believe there isn't a Chromium derivative with multi-select, table selection, and shift+right click. Containers are also incredibly useful.
It has at least one drawback. In the past there was an option to reload all tabs ( because every couple weeks Firefox starts begging to be restarted and after restart all tabs are blank ). Now you have to select all, reload, and not forget to de-select. If you forget and hit Ctrl+W you close all tabs.
Your pain points are real, but incidentally not relevant to me. Since I've been using FF nightly fulltime for a while I restart the browser (with session restore of course) quite regularly, mostly every day.
And I have the option enabled to confirm when closing multiple tab. Mostly because I sometimes hit Ctrl-Q by accident. Because conveniently, the "nuke everything" shortcut is situated right between the two most used shortcuts: Ctrl-W and Ctrl-Tab... :|
So yeah, I happen to not be affected by this particular problem :P
Vertical tabs is so much more space efficient than horizontal.