Pantheon is the window manager. Elementary is the underlying system, and if it was me, I wouldn’t bother tweaking it, since they’ve made so many opinionated choices throughout the system. I bet you’d pull your hair out getting things just the way you want.

It would likely be easier to start with a vanilla OS with common defaults and customize from there. If you just like Pantheon, check to see how easy it is to install on various distros (e.g. Fedora has a couple spins that use Pantheon, etc.), and test them out in a VM.