Yes, you're definitely using the wrong device, because the a1ide.device is for the internal IDE controller on an AmigaOne XE or SE or similar, i.e. the machines that were new between ten and fifteen years ago.
But it may be difficult to make DVD playing work on X5000 at the moment, because as far as I know the driver for the X5000 SATA isn't yet finished, especially in the area of handling optical drives.
Maybe someone has tried it and can give more info.
One possibility might of course be to put the DVD drive on a SATA card for which drivers have been known to work already on e.g. the X1000 (SiI3112, 3512, 3114 or such).
Best regards,
Niels