Stepan will only be traded for a good 1st line center still in their 20s. 86 overall 4.5 gold + only 23 so will have a chance to improve for 4 seasons.
Callahan I'd be more open to trading him for veteran players. He's on a cheap contract too.
to LightningGM: Nash is likely going to stay a ranger for entirety of the league but I would be open to making a trade as you have other players I like.
To WIngsGM: Callahan/Zetterberg swap is on table. zetter is 33 and will be 38 in year 5 so likely will regress. Callahan is 28 and will be 33 in year 5 so likely will remain as good as he is.