Although *buntu is in love with snaps (snapcraft) to deliver and update apps on any Linux distribution, it was time to have a look on the new QGIS 3.4 Flatpak package. And using Manjaro with a dated QGIS-version (and non-GRASS) in its repo, Flatpak is the quick solution.
Password managers like Keepass(I pefer KeepassXC)/Lastpass offer a nice choice to manage all your „accounts“ with different user/password strings and with very complex (and long) passwords. If someone gets access on your keepass-database and the password for it – bad luck. Authentication-Hardware like YubiKeys provide more security on your keepass-database and work like a charme on Linux.