Islanders don't have a ton of flexibility this summer - not necessarily a bad thing, depending on how they hold up in the playoffs. There's a section of the old core aging out but not completely gone, so personally I'd be making shorter-term, less explosive moves this summer to try and maximize what's currently here and unmovable.
--TRADES--
None. Stop trading the picks, Lou.
--RE-SIGNINGS--
Keep Sam Bolduc and give him a shot with Noah Dobson in training camp. If he doesn't work out, you have some depth (Robin Salo/Sebastian Aho) that is NHL-capable, and there are always guys available for a low cost trade if you really need a warm body.
Jakub Skarek is the 2B goalie to me - he's still young enough that be might unlock something, and is fine as a third option.
Wahlstrom is a key player to me - he looked good in limited minutes before getting hurt and I feel like there's something left to unlock. Give him top-6 minutes with two responsible vets to let his game grow, and let him work through mistakes instead of benching him.
Zach Parise and Hudson Fasching have been nice surprises on the bottom-6. If they're opening to coming back at contracts in this range, jump on it. I don't love the idea of spending much more on bottom-6 guys than this, so if they want a big deal, move on and go sign Zach Aston-Reese or whoever else you'll get at a similar AAV.
--UFA SIGNINGS--
Not a ton of open spots so not a ton of need to spend money here.
The biggest hole is Scott Mayfield leaving - Connor Clifton has played himself out of Boston's budget this year. His defensive numbers have been strong in his career to date; and this year he's shown some offense. If he'll take 4x$2.5M, I jump all over it. If he's played himself out of that tax bracket, then turn to a guy like Justin Holl or -gulp- see if Scott Mayfield will come back on a 2-3 year deal around this AAV.
Alex Nedjelkovic is a stand-in for the dozen or so guys that will be available in UFA for a similar cap hit this summer - he's shown some flashes and I think playing behind a solid defensive team like the Isles will help him regain his confidence. No need to overpay for a backup goalie - if Sorokin gets hurt, this team is toast anyways.
Lines are pretty close to how they've been this year. Top line is Horvat & Barzal with whichever winger you want to throw up there - I put Parise because I like Lee better on the second line with Nelson and Wahlstrom, but you could swap him and Kyle Palmieri if you want. Second line is veterans with Wally, for reasons outlined above. Third line is a strong defensive line - Pageau is having a down year but you hope he bounces back, and Holmstrom has been strong defensively. 4th line Cizikas with some combo of Martin/Clutterbuck/Fasching on the wings - I think the two old guys are still useful in small doses, and this would keep them fresh for as much of the year as possible. D pairs are the standard Pelech/Pulock, a strong two way pair in Bolduc/Dobson, and Alex Romanov being paired with a stronger two-way guy in Clifton.
No idea if this team is actually better than this year's - one would think getting rid of Josh Bailey might be worth 2-3 extra wins on its own, though.