Here's the reason why this team makes sense, and why it may not. The Lightning are working on a deal for Karlsson, and if this happens they will have a top 4 of Karlsson, Hedman, Mcdonagh and Stralman, which is a top two d in the league. To really make this work, they need to shed salary, and a trade for Patches (A superior player to Callahan in almost every way) does this. They add a sniper who can play all over your lineup and help an already deadly power-play. Already strong contenders, this would put them as HEAVY favorites. The price for this is Sergachev, a young defencemen that probably does not make his way into the top 4 because of the players ahead of him. Tampa also receives a solid puck moving, bottom pair, left shot d-man in Reilly and a 2nd in this trade. The Habs get younger and, while they actually add salary with Callahan, he is useful and provides leadership. I would make this trade. However, it would need the Karlsson deal to take place first.

Shaw is a trade to shed salary while providing leadership to a young Sabres team that lacks in this department (since O'Reilly left). This deal may not make much sense, but I do not feel it's horrific. That offence looks like the offence that will start the year and defensively this looks similar to the realistic team (With exception of Sergachev).

Please let me know what you think? Thank you!

Callahan has a 16-team no trade list, and I wouldn't be surprised if Montreal were on it. Also, the Lightning need Sergachev to get Karlsson. If they somehow manage to get Karlsson without Sergachev (it would probably involve Foote), and they do this, that team would be ridiculous. But, unless they include cap dumps in their trade, this leaves them over the cap. Add Killorn into it to keep them under (and maybe take away the draft pick since Killorn is another cap dump), and the Lightning will certainly consider it (they don't want to lose Sergachev and Foote, but if it means Karlsson and Pacioretty, it's worth considering). But, though the Lightning would be heavily favored for a season, they would be in a lot of trouble afterwards when Point, Kucherov, Karlsson, Pacioretty, and Gourde are all free agents. Next season would be Vasilevskiy, Cirelli, and most of their prospects that will hopefully be in a bottom forward role by that point. If they pull of a Karlsson deal without giving up Sergachev, they also may walk away from any other deal involving Sergachev. But Pacioretty and an offer to take Callahan isn't something you pass over lightly. This would be going all-in and accepting the cap hell that may come with it. There are many GMs who would do that, but Yzerman probably isn't one of them. It would certainly give him something to think about, though, and nobody should be surprised if he accepts an offer like this.

More likely, though, the Senators demand Sergachev if they're giving Karlsson, and unless you'll take Foote instead and do the same deal, this doesn't happen.

Habs could then turn Callahan to NYR for Beleskey and 2 millions retain or some sort of ahler to fit both needs?

It should be stated that, clearly, this trade is not going to happen. However, I think it would be a deal that makes sense. I agree with you, I_know_nothing, about the Sens requesting Sergachev in the deal. However, I also think they will inquire about Brayden Point. Either one of those two players are interchangeable. I could see a deal that that the Sens would require: Sergachev/Point, 1st round pick 2019, Foote, and maybe a 2nd round pick). If that is the case, they are up it big time in terms Salary Cap. The trade for Patches gives the Lightning around 1.5 million in extra space, and Sergachev (LD) is going to have a hard time fitting into the top four in TB, where they have two LD's ahead of him and signed long term.

Looking on the deal, I should have included another 2nd round pick (2020) into the trade. However (I think) if all the pieces fell into place, it would work. AND the Habs could absolutely trade Callahan to the Rangers for some AHL player and a 2nd/3rd round pick. Again, this is just a conjecture trade.