I wouldn't be surprised to 8 D in Columbus, although clearly a log jam on both D and F so one area is going to have harder decisions to make (I think that's up front). As for Cleveland, assuming Jiricek and Blanks are sent down, I have a hard time thinking that Jiricek, Svozil, Blanks and Ceulemans don't get a LOT of playing time. I think Berni has shown (if he clears waivers if sent down) that he's worthy of a future option (7/8 or even bottom pair guy but maybe not in Columbus). They like Christiansen too but he's starting to become that AHL+ type player so maybe they don't feed him the time.
What I would expect is you could see Berni stay as the 8th in Columbus (barring no injuries to the others) and the others stick in Cleveland with a heavy rotation. Wouldn't shock me to see a prospect moved in a multi player deal to free up some space in Cleveland as well. While I think all on your list offer some value, I don't think a waiver loss of Christiansen, Bjork, Sweezy would have too significant an impact to the club overall. Depth... sure but If they keep the top 7 and have Jiricek, Blanks and one or two of the others behind them availabel for injury duty that still provides 10 deep on quality defensemen. In my opinion... The depth, as shown, goes beyond 10 with NHL potential (just a lot of green back there)