Changes:
Moving Alexis Lafereniere to the first line.
Moving Kaapo Kakko to the second line.
Justifications:
Lafreniere is a north-south player. This is the same style that Kreider and Zibanejad play. Thus, I believe they can read off each other better, also with a change that line can be jump started.
Kakko is an east-west player. This style is played by Panarin, and Trocheck. Thus, making this change can lead to more scoring chances and shots for that line. Also, Kaapo is an incredible puck handler in very small spaces, Panarin is the greatest (or one of them) in the NHL, and Trocheck has a wicked shot. This line sounds good!
I'm good with your top two lines. Laffy fits with KZ's tools and Kakko can be a strong net-front presence on 2L. Blais is having a hard time shaking off the rust with his O after returning from injury and he just needs some time to get it right. Vesey is better on the 4L and Blais should get time there as well until he steps up his game. I would like to see game-day callups on Rydahl and Trivigno to see how they fit in on 3L. Trivigno was signed for O upside, so let's see what we have and if he can fill the void left by Chytil injury.