I think everything is fine.
Synaptic will reload repository list after installing Sparky on a hard drive and removing lsb-release file. It needs to rebuild intramfs and/or grub list as well, to let the system be recognized as Debian not Sparky.
The terminal issue - the root password is blank, means you can't log in as root.
To do so run:
It will let you create the root password.
Anyway you can run applications with sudo command to get root access as well.