On Chrome I rely on 3 extensions: 1Password, uBlock Origin and Vimium. I obviously don't need Vimium on Qutebrowser. I could possibly get by without 1Password if I switched to something like Pass. However, I can't give up uBlock Origin. I run it in "medium mode" (3rd party frames/js blocked by default) and I can't give this up.
I would pay decent money to be able to run uBlock Origin on Qutebrowser.
I'd absolutely like something like uMatrix in qutebrowser (see [1]), and since I recently started work on a plugin API[2], that'll hopefully happen soon-ish.
As for password manager integration, check qutebrowser's userscripts[3] (which are unrelated to Greasemonkey scripts), but a plugin API should provide a better foundation for that as well.
[1] https://github.com/qutebrowser/qutebrowser/issues/28
[2] https://lists.schokokeks.org/pipermail/qutebrowser-announce/...
[3] https://github.com/qutebrowser/qutebrowser/tree/master/misc/...
However, since I stumbled about this project, I've got no need for that anymore: https://github.com/purduelug/passhole
I really like the suckless approach to GUIs in this case. Yes, you don't get stuff like automatic url matching with this, and you have to manually add new entries, but its functionality is works great for me nontheless.
Maybe, there's also an easy way for you to get (or write) a dmenu interface for 1password?
Run :adblock-update to download adblock lists and activate adblocking