Reaves is a side issue- I would insist on sending back Jost, or Steel if he is included, because we'd just have too any forwards.
As for the Laf for Zucc? I would do it in a heartbeat, not because Zucc hasn't been great, but because there is 15 years between the two of them, and, IMO, Boldy could step into Zucc's spot without missing a beat. Laf has been a disappointment so far, but his age fits out timeline far more than Zucc's. It sounds crazy to me that NYR would be willing to do it, but if they feel that this is the year that they can make a run(or two), then it might be worth it for them. He has proven that he likes playing in NY, and I think that he Panarin could have a lot of the magic that he and Kap have.
So, as crazy as it sounds, this deal might actually work for both teams.