I plan to cut holes for the fan on the lower right side of the removable panel, as close to the front as I can. It will be blowing on the lower part of the motherboard, and plenty of fresh air should move up to the motherboard heat sink and the cpu heat sink.
Hopefully the material is not too hard to drill. Why make a removable panel very hard?
Per above advice I won't worry about the optical drive and the hard drive.