Hi Ben,
I deleted the VM and created a completely new one, though on the same host, which I currently cannot change. Installing the linux-image-3.16.0-0.bpo.4-686-pae kernel results in no way to boot the VM with neither dracut from wheezy nor initramfs-tools from wheezy-backports. Please see the attached picture for details. The host cpu is basically maxed out during the time the VM is in this state.. Kind regards, --Toni++