So it’s only logical that my default shell is the one the guide is about ;-)
What annoyed me majorly was that in Gentoo Linux, the delete key did not work in zsh (unless of course you count outputing ~ instead of forward-deleting as “working”).
Finally I got around to fixing that.
bindkey "^[[3~" delete-char bindkey "^[3;5~" delete-char
to your .zshrc enables your delete key on every thinkable keyboard. Finally!