I am using an asus m4a88t-m and builtin controller AMD SB710. This board (after some googleing) appears in other peoples freenas builds. Additional evidence that I this should be OK, I can see the drives in via "View Disks"
I have seen indication that disabling SMART would help as some of the errors in messages log (above) appear HDD related.
The dd failed as there is existing metadata on this drive, the OS is protecting it. Wipe the drive with DBAN or the like. I would try a quick wipe first via the GUI.