Updating Manjaro as safely as possible / logging out?

You can download the updates with:

sudo pacman -Syuw

The w tells pacman to download only and not install updates. Later in the console you can just run:

sudo pacman -Su

that install the already downloaded updates without synchronizing with the repositories

I’m also used to run:

sudo systemctl isolate multi-user

before updating to stop the graphic environment. It’s not necessary, but I feel that it’s safer for the desktop environment. Do it when you are in the console after logging out from the desktop environment

It could maybe be expanded to the aur with something like:

mkdir -p ~/aur-update && cd ~/aur-update && paru -G $(pacman -Qmq) && for d in ./*/ ; do (cd "$d" && test -r PKGBUILD && makepkg -src); done

-drop to tty or stop graphical environment, et al-

cd ~/aur-update && find . -type f -name *pkg* -execdir sudo pacman -U {} +

(this is also relying on paru to download the PKGBUILDS … I assume other helpers may have similar options)

Yes, but probably not a good idea to have any core component built from the AUR. My AUR packages are just normal apps that I can update from the graphical pamac tool if I want (after I have updated the system from official repos)

That depends, what if you’re blind?
… or, otherwise inebriated …