I nerded out with my spreadsheet (yes, I have a salary cap spreadsheet), so sorry for the long post.
The forward group is going to have two opening night roster spots open, a third if they don't re-sign Dadonov. There is no way to fit both he and Domi on the roster.
I think you bring back Dadonov. He'll be cheaper and won't get as long of a term as Domi will. Why bring Dadonov back? His play and locker room presence were outstanding since getting here. As much as we're all excited for the youth movement (guilty as charged), after talking with some folks after the game last night and today, I was told it's a bit optimistic that more than one young guy will come up and stick with the big club next season. It makes sense. Bourque has 1 AHL season under his belt, and Stankoven has never played with grown men. Either one may need next season or least part of the season in the AHL. Either way, you can't go into camp in the fall EXPECTING both to stick. So for argument's sake, let's say one of the two is on the opening night roster. That leaves your forward group as follows:
Hintz-Robertson-Pavelski
Johnston-Benn-Dadonov
Bourque/Stankoven-Marchment-Seguin
Faksa-Glendenning/Kiviranta/Olofsson-Dellandrea
Glendening, Kiviranta, and Olofsson are all UFAs. There's no reason to sign more than one, if any. I'm assuming they'll sign one though. Dellandra is a RFA, so he'll get some sort of offer that shouldn't be too unreasonable.
On defense, like has been said, you're locked in with your 7 guys. Hanley is a UFA, left-handed dman. He's out.
Assuming my projections, you're right up against the cap. I mean, RIGHT up against it (depending on the Dadonov, Glendening/Kiviranta/Olofsson, and Dellandrea deals of course). That is unless the cap is higher than the projected $83.5M which is looking like a distinct possibility.
You could leave Dadonov off and have some space, but then you have another forward spot to fill. Youth movement sounds good, but that's a big gamble. There's also the possibility of a Suter buyout, but with Johnston, Bourque, Stankoven, Harley, Lundkvist, and Oettinger all needing new deals by the end of the 24-25 season and Robertson needing one at the end of the 25-26 season, that dead money could come back to bite you.
Other than a buyout, I would try to bury Suter on the 3rd pairing. Play him under 20 minutes per game and take him off special teams. With a manageable workload, maybe he won't look quite as bad. Then I'd try and trade Miller, Hakanpaa, or both. Easier said than done, I know, but they're ok defensemen on low, expiring contracts.
So, let's say the cap is really $84M, you can shed Miller's contract and get Dadonov at a reasonable amount. You could conceivably have over $3M to go out and get a defenseman. I could live with a lineup that looks like:
Hintz-Robertson-Pavelksi
Johnston-Benn-Dadonov
Stankoven-Seguin-Marchment
Faksa-TBD-Dellandrea
Heiskanen-Harley-Lundkvist-Lindell-Hakanpaa-Suter-TBD
Oettinger-Wedgewood
If Stankoven and Bourque were both ready to roll, I would have no problem sending Marchment to the 4th line. That would make for a crazy talented top 3 lines.
I will say, the way the contracts on this team are laid out, is fantastic work by the front office:
Pavelski, Miller, and Hakanpaa come off the books in time for Lundkvist and Harley to get new deals.
Benn, Faksa, Lindell, and Suter come off the books in time for Johnston, Bourque, and Oettinger to get new deals and a year before Roberston and Stankoven need new ones, when Marchment also comes off.
This team is set up for long term success. Just don't be too shocked if next year's roster looks almost identical to this year's. This team's true peak is still ahead of it. That's why this year was such a pleasant surprise. They certainly exceeded my expectations going into the season.