Mouse & Touchpad Separate Settings Missing

You have installed libinput. It is used instead of xorg-synaptics to manage the touchpad.

Unfortunately current Ubuntu with Unity DE does not have libinput settings GUI by default. unity-control-center can control only of xorg-synapics.

Another option is to uninstall xserver-xorg-input-libinput package and use xserver-xorg-input-synaptics that is installed by default instead.