Well, to hare off into wild speculation, Reek could be a corruption of Ric, a diminutive of Domeric. Which, if so, would make Roose Bolton much, much scarier and creepier than even his bastard son, Ramsay. I think that the Boltons are there to show the reader that as awful as they may have felt Theon was, there are worse people out there. What Ramsay has in mind for Theon's assistance down the road, I cannot guess. But I do not think that the Bastard of Bolton is any real match to the cold, calculating and terrifying Lord Roose.