One last update for my homebrew NAS-
The drive issue (constant accessing) magically disappeared last night after a message popped up relating the completion of the RAID5 sync following the OS install. Go figure- it was working on something the whole time.
However, trying to install the drive spin-down package failed and pointed to problems with my 'locales' that I'll attack soon.
Happiness ensues!

and- since the RAID5 sync finished the transfer speed has nearly doubled to ~90MB/min!