That Mahle trade is awesome of the Twins, no way the Reds do that. If they do get Mahle, I move him to the pen and make him a 2 inning RP. That's way less than the Twins got for Berrios, and it isn't close.
I'm not too keen on trading Steer at this point, not for a rental at a position that the Twins might be ok at (DH or 1B, given how often Buxton and Arraez DH and AK is the 1B).
I'd do the Bard deal.
I just think all those moves together deplete the hitters in the minors too much. I'd much rather give up Ober or Enlow or Balazavich than all of Steer, Wallner, Martin (who I was clearly too high on).