I absolutely think that Ottawa should go into full rebuild mode and should definitely trade away their impending FAs and maybe even some controllable guys as well. That being said I don't totally understand your deals:

1. Karlsson trade- I get that Heiskanan is one of the top prospects in the NHL and just 19 years old, but this seems like the weakest return of the 3 impending FAs. While Heiskanan is a top prospect, there is also the most uncertainty with him as well, as he's yet to play in the NHL. With Faksa as the only other piece this feels kind of like a soft deal, especially compared to the other impending FAs who I think have less value on the trade market (if we are assuming they are all signing extensions).

2. Duchene trade- Duchene is a good center and an upgrade over Wennberg, but adding in both Milano and a 1st seems like too much. Sure an extension is part of the deal, but the Blue Jackets are giving up quite a bit for a guy who would be set to be a FA otherwise. Wennberg's contract may be a bit underwater, but he's shown promise and is still pretty young and Milano could have a very bright future at a cheap price. Add in the first and this looks like a lot for CBJ to give up, esp. since it probably hurts their postseason hopes this season not helps them (and going forward).

3. Stone & Ryan trade- Even ignoring Ryan's negative value for a minute, giving up Tuch, Miller and a 1st for Stone is quite a bit. Sure Stone is a really good winger and he should be an effective scorer for years to come, but he's also going to get paid big time. He might be looking at an $8-9.5M a year salary range (probably would take the high end to get him to forego UFA) for 7 or 8 years. Vegas would be giving up 4 years of Miller on a pretty favorable deal and 5 or 6 years of Tuch's team control, the first few of which will be cheap. That just doesn't really make sense and again would look to hurt Vegas' playoff hopes. On top of that they have to take on the terrible Bobby Ryan contract.

4. Ceci trade- This I don't get at all, Ceci is a good defenseman with two years of team control remaining and you trade him for 1 year of Brock Nelson. Unless you meant to extend Nelson long term I don't get it. The Senators will be bad this year so Nelson would be a waste.

Everything you wrote is spot on, well said.