Earlier quoted context omitted.
Libvirt and virt-manager are just simplified user interface to the real software, which is qemu(and KVM). They solve pretty trivial problems, like parsing config file and passing the right options to the qemu binary. Yes, they have some additional useful administration features like start/stop based on a config file, serial console access, but these are really simple to implement in your own shell scripts. Storage ha…
You've missed the point of libvirtd.
That's possible, but you also seem to have missed mine, which is libvirt is not great time investment if you want to learn how qemu works, or have the most flexibility and control in its deployment.