Lengthy process of reinstalling? Have you ever installed VMware or Hyper-V? proxmox installation is superfast.
If you have installed ZFS and created a snapshot after the installation, then yes. Without knowing what you changed, it's hard to tell, but cleaning up /etc/pve should work. It would be best to have another empty proxmox ready for comparison.
Alternative: uninstall all proxmox related stuff with --purge and reinstall it. This should yield an empty install.