There’s hotkeys for workspace navigation, I use them all the time: Super+Alt+Left/Right will navigate to the next/previous workspace (Super+PageDown/Up also works). If you go in Settings -> Keyboard shortcuts -> Navigation you’ll find more, notably to move windows between workspaces.

As for the fullscreen by default, there’s extensions for that I guess, though personally it doesn’t bother me since after the window is maximized once it should restore its maximized state the next time it’s opened. With Super+Arrow keys to position the window, I personally barely use the mouse for window management.

Qalculate!, the calculator I use every time I need to do a calculation, especially if it involves units or currency conversion. Does everything I’ve ever needed out of an everyday calculator (even symbolic calculation and exact results), while keeping the usual simple calculator interface.

The Nextcloud AIO container itself doesn’t have access to the backup directory, but it has access to the docker socket (/var/run/docker.sock). Having access to the docker socket means it can perform any docker operation on the host system, in this case starting a separate backup container with the backup directory mounted.