It’s the NHL, at some point you have to be ready to pay good players. If not, then you have no business having a NHL team. Many other cities wants to have one, it’s a privilege
You don’t trade Stone to be able to re-sign Duchene and EK. Sens are barely at the cap floor right now despite MacArhur 4.65 cap hit who is 80% insured. Gaborik 4.875 will also be off the books sooner than later (LTIR? Retirement? Buyout? Trade?). You can also trade Smith for a pick or something and replace his 3.25 by a younger cheaper player. Ryan’s contract is getting shorter every year, and if he can stay healthy a full season, then it becomes easier and easier to move (just retain on his salary and replace him by a cheap young player if you absolutely have to save money). Anderson, Condon and Boedker also have only 2 years left... Money will come off the books or could come off the books like crazy in the next few years. They could easily afford to have all of EK, Stone and Duchene assuming they stay reasonable in their demands (7-8.0 per for the forwards, ~11.0 per for Karlsson)
That should be plan, build around those 3, Chabot and then the prospect pool should fill the rest nicely. Then you already have a few quality young supportive players like Dzingel, Pageau, Ceci (if used correctly)...
1st liners : Stone, Duchene, ???
2nd liners : Dzingel, ???, ???
3rd liners : Pageau, ???, ???
#1 D-man : Karlsson
#2 + #3 D-man : Chabot, ???
#4 + #5 D-man : Ceci, ???
Need 15 quality pieces to have a good team, there’s already 7 there, need 3 top-6 forwards, 2 good third liners, a #2-3 D-man and a starting goalie. The prospect pool will provide several of these pieces. If 4 are better than Dzingel (Tkachuk? Brown? Batherson? White? Chlapik?), then it brings him to the 3rd line which is ideal
Formenton-Pageau-Dzingel could be a formidable 3rd line and one of the fastest line in hockey, could drive other teams crazy with relentless forecheck.
In conclusion, if they can build around EK, Stone, Duchene and Chabot, I am very confident in the future of this team. If they deal some of them, then we’ll need to hit some homeruns with the young guys acquire and/or the ones we got.