If I recall correctly, Mangiapane was playing at RW with Michael Bunting at the worlds. Dubas was there as part of Team Canada, so I believe that is where all of this is coming from. Mangiapane would be the RW on the Bunting-Malkin line. I don't remember who played center on that Team Canada line, but it was not John Tavares I do not believe.
I don't see the motivation for Calgary to trade Mangiapane for Smith, and I don't see the motivation for Smith to accept a trade to Cgy. And we sure as hell should not think about trading away futures for a player like Mangiapane. And would we even want to re-sign him? We would be acquiring a guy now to trade for futures at the deadline? I really don't see this as a fit.
Skinner does nothing for us if he is a UFA. As a retained salary acquisition with future assets thrown in, he absolutely has value to us.
I think Wahlstrom is at least a decent bet to not be qualified. The Isles would need to throw him into a trade to make that work.