Not worried about Kakko. He's like 6 months older than Lafreniere.
They need to make sure he plays on a line with chemistry, however. I think he'll be best on a possession line that likes to hold the puck in the offensive zone and wait for high quality chances.
His transition game through the neutral zone is weak right now, and so making sure he spends as much time as possible in the O zone should help him out. Question is whether that's more likely to happen with Zibanejad or Panarin's group.
What was concerning was that every blueliner last night was a shit show, and everyone was struggling to make proper breakout passes. That can be a rust issue, but it's also a scheme issue. Our guys are going to have to be able to deal with forechecking, and if they can't, the center needs to come back deep and give an outlet.
As for the line rotation and PP choices- it's gonna be a very accelerated season. Minutes are gonna have to be spread around.