Mac compatible DVD drive is not the problem. The problem is the Mini9 is very picky about which DVD drives it will boot off of.
As for the disk utility, yes, you need to run that, go into it, select the SSD
, go over to paritions, select 1 partition from the left side of the partition window, then when you do that, you can click on options at the bottom left of that window and choose GUID from the list of 3 options. Close that window, click apply in the bottom right of the partition window. Close disk utility, you may need to hit back and then forward for your partition to show up on the installable list. No reboot required. Then just install.. You'll need to boot off the Type11 thumb drive or USB stick one last time after installing to boot, but then you finish the last half of the Type11 instructions and you're golden. You're getting closer.. Just think of how much you're learning in this process. That's never a bad thing.