Agreed, they should be adding/retaining as many quality players as possible.
Farmer is arbitration eligible, he's probably going to get a big enough pay hike that the Reds would not keep him as a bench player.
Really, starting the season with farmer as the 3b isn't that horrible of an idea. Make the kids force their way into lineup instead of handing them the job (ready or not)
Make Steer or Strand really bust the door down to get in the lineup.
Also, it's nice to have Farmer on the roster in case Barrero gets hurt.