Probably not very realistic but this would be my attempt to re-tool:
Trade Greenway+Zucker and use the return to get Murphy from Blackhawks.
Trade unprotected 2025 1st+Rosén to get Rasmus Andersson from Flames.
Trade Peterka, Krebs and Byram to get EP from Canucks.
Sign Granlund and Tanev in summer.
Kulich-EP-Tuch
Benson-Thompson-Quinn
Granlund-McLeod-Cozens
Malenstyn-Laffertty-Tanev
Dahlin-Andersson
Power-Murphy
Johnson-Clifton
Samuelsson
UPL
Levi
These would be my tweaks on your re-tool:
Trade Greenway. I'm assuming it would be a contender who is interested so likely a 2nd or 3rd round pick in return.
Resign Zucker. If price and term are reasonable. He's the kind of vet we need and offers versatility up and down the lines.
Trade Cozens and Krebs for Andersson. Calgary is desperate for centers and both fit the age range they're looking for. If an additional sweetener is needed to get the deal done, so be it.
Trade Power, Kulich, and 2025 first pick for EP. I'd rather switch Ostlund/Helenius for Kulich but I'm guessing that's who Vancouver would want.
Free Agency: There is a dire need for some toughness on this team. I'm doubtful how realistic Olivier and Frederick are as targets (especially Olivier), but those are the types I would be looking for and would be willing to overspend on. Dahlin needs a partner.* There seems to be a consensus that Fabbro would be a good fit.
*If Fabbro doesn't work out, perhaps Whitecloud would be available if Vegas needs cap space. With Andersson's ability to play on the first line and Dahlin's ability to play the right side there should be sufficient flexibility to fill out our top 4.
Trade Lafferty in the summer.
Peterka -
EP - Tuch
Benson - Thompson - Quinn
Zucker - McLeod -
Olivier
Malenstyn -
Frederick - Kozak
Dahlin -
Fabbro/Whitecloud
Byram -
Andersson
Johnson - Clifton
UPL
Levi