Re: Dealing Dahlin/Stone
Definitely not. You'd be giving up one of the best Dmen in the league and a top two-way forward for three unknowns (and the 2023 1st rounder probably won't help you for a few years so that player is about five years away from being remotely relevant if at all). It's not as if they're high picks either as the team you're dealing with is trying to contend so you're looking at low first rounders too.
As Eskimo Brother said, depending on your league format that possibly is a deal for one, but definitely not both and regardless of the format I'd stick to your proven players. Dahlin and Stone are great and are worth much more than what you're being offered.
And welcome to the forum! It's great to pass around ideas here and get feedback (but ultimately make up your own mind as it's your team and hey, you're supposed to have fun in this thing anyway). For future, put your team in the signature (it's in the Settings tab) and also tell us whether you're competing or in a rebuild, and what the league settings are (how many teams, what stats count, is there a salary cap and if so how much, any restrictions on how many players, etc.). You'll get a better answer (and reasoning) that way.
League 1
Keep 16 - 4 rookies max 162 GP
Forwards: Point, Tavares, Svechnikov, Boeser, R Strome, Teravainen, Tarasenko, Arvidsson, Tolvanen
Defencemen: Boqvist, Hamilton, Dahlin, Klingberg, Ekblad, Hronek, Marino, Brannstrom, Shattenkirk
Goalies: Vasilevsky, Shesterkin,
Minors: Kravtsov, Tolvanen, Brannstrom
League 2
Keep 18 - 4 rookies max 162 GP
Forwards: J Hughes, Kakko, Cozens, Frost, Kubalik, M Tkachuk, Vrana, A Svechnikov, Virtanen, Buchnevich, Gurianov, Tarasenko, Lehkonen
Defencemen: R Andersson, Jokiharju, Trouba, Valimaki, Cholowski, Leddy, Montour
Goalies: Saros, Sorokin, Talbot
Minors: Heponiemi, Krebs, Tippett, Hoglander, Liljegren, Bouchard,