Trade:
Not sure what the leafs could get for Johnson but I'd move him for draft pick to clear cap space as the leafs have a lot of depth on the wings.
Signing:
Dylan Demelo could be use as a stop gap until Lilegren is ready. Not sure if he'd be able to take a step next year and Demelo has proven he could be steady dman on a potentially cheap deal. Obviously, if there was another option on upgrading that position (ie. severson trade) i'd do it. However, the asking price will be high and It wouldn't make sense for rebuilding teams to move young valuable defeceman unless there is an overpay. A potential trade I could see is Dermott + Johnson + 2nd rounder for Severson.
Depth Signings:
This is a key summer for Dubas to solidify a strong AHL/ECHL group the the leafs can rely on. There will be less attention on the main roster as a lot of pieces are already locked up long term. There needs to be more consistency from depth players as Pittsburgh, Tampa, Columbus and Boston have shown. This could be the difference maker for having an easier path in the playoffs. I feel this is an area Dubas has shown he is strong in, which he needs to be to make up for his poor negotiation skills on big contracts (Marner especially). I understand the Tavares signing. Mathews could've came in at $10.5M - $11M but he prove his value at $11.6 I believe. Huge fan of Nylander contract regardless of the first poor year. All in all, probably lost around $2M in cap space form these contracts which is reasonable looking around the league.