I would say flip Laine and Marchenko as well as Kuraly and Voronkov. I would love to see a KJ Marchy duo build some chemistry, but on a line with Bedard I think he wouldn't get to blast as many shots as he'd like. Which would be perfect on that first line. Laine if he keeps playing like he was this past season especially while playing center could benefit from a playmaker like KJ and another goal scoring threat to draw the focus to Bedard giving him more space in theory. And that 4th line was so good this year, don't mess it up until it stops working.
Lastly, if Ros is a healthy scratch, he's gonna get traded, if he can't keep his spot he needs to get moved.