No idea on the DVD errors. Check the output from dmesg after you try to mount the drive. Also check the output from lsmod after you try to mount the drive. HFS+ support is probably compiled as a module and would show up.
If you followed every step it should be working. I haven't used versions of YDL after 3.0.1 (no new Macs
). Their instructions looked almost exactly as I'd describe the process (except I'd order things different, 'mount -t hfsplus /dev/hd?? /mnt/macosx').