You maybe able to uninstall gnome-setting-daemon, but when you try to uninstall gnome-settings-daemon-schemas, you 'd be asked to use autoremove and remove lot of unity specific packages. So, these packages have to be specifically reinstalled. That is, apt won’t be able to uninstall them (specifically installed) in an upgrade.
This means, in the future, you may have to create a meta package, something like unity-session, which would pull in all the needed packages to run Ubuntu-Unity, the minimum system with Nautilus and System settings. The rest are additional applications, such as Libreoffice, Evince or even Calculator. Of course, they can also be incorporated in the meta package.
Now, that the live iso is working, it is time to start from the mini iso (netinstall) to find out what packages are specifically needed to create the Unity only Ubuntu. Actually, the last Unity only Ubuntu 17.04 iso would show what packages are needed. The ubuntu-desktop (meta-package) in that distro most probably has the needed info. It is still available until January 2018. The netboot can be found here, http://archive.ubuntu.com/ubuntu/dists/zesty/main/installer-amd64/current/images/netboot/