My crude run down of what I think needs to happen would be:
Shanahan/Treliving/Coaching staff gone. I just don't know how you keep Tre and bring in a new president. I think Brandon Pridham moves on too. Coaching staff goes without saying.
I'd look to move Marner and/or Tavares. I think Marner is more likely. Tavares likely walks for UFA or takes a significant cut on his next contract. I'd explore trading Kampf and attempting to use his money for a cheaper alternative.
UFA Forward: I'd look to re-sign Domi, I think Bertuzzi will be too in demand at free agency although I think he's someone this team needs too.
RFA Forward: Robertson and Dewar back for cheap. Gregor goes.
*Not lines, just depth as it would stand re: NHL talent under the assumption Marner/Kampf move on*
Knies - Matthews - Nylander
Robertson - Tavares - Domi
Jarnkrok - Holmberg - McMann
Dewar - XXX - Reaves
*Jarnkrok makes so little that I think his value would be better for us than in trade. Reaves I just think will be here or waived. Not sure what a trade for Marner brings back but it's likely some roster players involved so they will probably slot in somewhere in these lines. Maybe a Cowan, Mitten or Grebyonkin make the roster out of camp, but I don't think they'll avoid adding to the roster in hopes those guys make it.
UFA Defense: All walk. I could hear arguments to keep Edmundson or Lybushkin but I don't think financially it'll make sense. Last potential cash in contracts for both with a rising cap.
RFA Defense: I think Liljegren will be traded. The contract renewal will likely be a sticking point unless they really grind him down short term (1-year). When he got scratched in the playoffs I think that was the writing on the wall for him.
I'd look to move Rielly to see what his value is but they don't have puck movers to begin with so likely stays.
*Not lines, just depth as it would stand in terms of NHL players under contract*
Rielly - XXX
Benoit - McCabe
XXX - Timmins
*Leafs need to go big game hunting on defense (pushing Timmins down the roster). Whether that's in the form of a Marner trade or trying to land someone like Matt Roy out of LA as a UFA. I'd like Carrier out of Nashville too if going the UFA route.
UFA Goalies: I think they all walk.
XXX
Woll
Think they need to bring in a legit starter via trade. Woll's injury problems are just that and they need a guy who can do 50-60 games solid (Saros, Markstrom types). Marlies will have a young group coming in next year if Peksa sticks around and Akhtiamov joins Hildeby. Think Hildeby is your #3 vs. bringing in a vet like they did with Jones.