Hi everyone, I'm here to share some information about this issue.
I faced the same problems as you but I tried to go further. Everything looks fine when booting from DVD, it shows some error while loading the OS but in the end instead of crashing with the "Unable to find a medium containing a live file system
", it switches automatically to the USB loader I also plugged with a bootloader I've made with dd on Mac OS (search dd loader usb img mac you should find the command line to do it). So it finally boots and shows me perfectly the desktop.
So let's go forward and try to install the the OS on your hard drive disk. Fill the blanks, enter your name, keyboard preferences, then let's install ! And here, it tries to copy the first file and then stops here ; the DVD does not seem to turn anymore, and the USB stick does not show any read/write on it. So, have anyone achieved this installation ?
I just mention that I have a 2011 Macbook pro.