As much as I want to offer Marner the world don??t see it happening

Don't think Bruins trade Carlo. Although the Leaf trade is fair, it doesn't help the Leafs cap all that much. But Nylander for futures might to it. Andersson, if he still deemed a good NHL potential, and the two picks as you suggested.
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Fabbro most likely won’t be moved by Poile, and Tolvanen definitely won’t be moved. Preds aren’t giving up their two of their best prospects for a top 6 forward.
As much as I would love to do the Carlo trade, I can’t see Boston accepting. Carlo is worth more to them than we think, so I bet they would decline too.
Toronto trade is interesting. I can’t see Nylander being traded after his monster extension though. I, for one, would not want his contract on my team, as it would be a long-lasting burden. He’s a great player though, so if Gorton wants him badly, he could go for him with a deal similar to this. Most likely Namestnikov or Shattenkirk would replaced with a solid and more consistent roster player.

Nashville trade is just brutal.

If David Poile didn't want to give up Dante Fabbro and/or Eeli Tolvanen to acquire potential rentals in Matt Duchene and/or Mark Stone, there's no way he'll trade Tolvanen AND Fabbro for Kreider.