Okay I'll bite.
Best defenseman - Quinn Hughes (tough to not name him; with the improve depth of defensive D-men and the quality of forwards, I think they can just have him focus on his strengths, as the guy who keys the transition from defense to offense, compared to last season when he was overworked at times and tried to do too much; with a solid defensive partner, along with OEL for secondary offensive duties and hopefully OJ taking tough matchup duty, and more capable forwards throughout the lineup, the chances for a positive impact should be greater than last season) HM: any of OEL/ Myers/ Hamonic (all 3 have potential if they can handle their role, and if they flourish in stabilizing their own end and also score some points, they could challenge Quinn for the title of best defenseman -- just like some had Schmidt last season as one of the best due to his all-around play after the rough start)
Breakout candidate - Vasily Podkolzin (the tools are all there -- size/ strength, shot, passing, drive to the net, defensive awareness; I wouldn't be surprised if he does end up on PP2 and can be effective on there due to his versatility) HM: Jason Dickinson (after not having a 3rd line shutdown C for quite awhile, I think we'll appreciate as fans how much he can shoulder the brunt of the responsibility that was essentially miscast on Horvat -- if all goes well we could have a Malhotra (minus the faceoffs, for now) who also might have some offensive ability)
Bounce-back candidate - Tucker Poolman (at least stats wise, unless he scores zero points, and unless both he and his LHD partner forget how to play defense and get cratered, Poolman can probably improve from his 1-point season, and if he keeps his game simple, there's no reason why he shouldn't or can't just let any of Hughes/ OEL/ Rathbone/ Juolevi move the puck up ice while just being the rock on the back end; the season before he had 16 points in 57 games so his offense isn't non-existent plus there has to be a reason why he's a 17-18 minute defender). HM: Hughes (we know the scoring's there, but he just needs to not turn the puck over so much, and with the talented offensive group, and Shaw's system, I think he can have better +/- and make fewer eye-popping defensive mistakes)
Decline - Jaro Halak (with the pricey vets gone, I think he'd be a reasonable choice; most of the other players are on the upswing or prime of their careers, and while Hoglander may end up on 3rd line minutes, I think that's not a decline as much as a change in role e.g. focus on being more responsible and counter-punching which is important too) DM (Dishonorable mention): OEL (I think there's a risk that previous systematic issues on our blueline still remain, and I think OEL is primed to take on Edler's role as the tough minutes LD; if things go rough in his own zone he could look pretty bad)