I only have anecdotes re: Julien and Kessel/Seguin. Well, one anecdote and one observation. With Kessel, apparently Julien didn't like his work ethic - the anecdote I heard was that he questioned why Kessel didn't work out more off-ice. So if the coach fundamentally doesn't respect you, playing with commitment is going to be a challenge. I don't remember specifics re: playing him or not playing him. Julien is known to have a short leash with some youngsters (except, curiously, with Jordan Caron, who played well beyond his expiration date, typically as a fourth line grinder).
With Seguin, I remember the book on him was that he just wasn't good defensively, that is, getting back when offense turns to defense. In Seguin's last weeks with the team, he looked timid, and awful. He would enter the zone with speed, as if to start a play, and then fire the puck, or look for an easy pass, and start cycling from there. He showed no creativity, as if he didn't want to go too deep into the zone. I think he was scared to make a mistake.
No one knows - or at least I don't know, why they got rid of Seguin, but management is still taking heat for trading, in essence, a horse for "ponies." I would guess that Julien had something, or a lot, to do with that. Funny, Julien loved one of the ponies we got back - Louie Eriksson - who's now wasting space with Vancouver.
The only parallel with Galchenyuk is the seeming lack of respect for what he does well, shown by shifting him back and forth to the fourth line. My guess is Julien will want Galchenyuk - and Drouin, for that matter - to work harder defensively. See if that stifles their offensive spirit. That's what I'd watch for.
