Did you also see Marchand's spin move in the third period?
Here's where 'narratives' are not a path to appreciating a sport more deeply - the Tampa Bay paper described that play as "the Lightning refusing to react to Marchand's antics." People who know hockey (like, say, Sid Crosby) know how good he is. You may wish to reflect upon the strangeness that a large part of Marchand's 'reputation' comes from his licking of opponents. And while that's against the rules, I'd say the reaction to it shows a ton of homophobia.
In addition, Marchand's game changed quite a bit after the World Championships ... not realizing that shows casual fandom.
Hitting is part of hockey. Tampa last night gave Kuraly a good whacking, and I don't see anything wrong with that play (and I'm glad it wasn't called, and honestly, they really shouldn't have reviewed it). The true cheap shots tend to be things that aren't arguable. Matt Cooke ending Marc Savard's career; Tie Domi skating onto the ice and going headhunting; etc.
Should I dislike Nazr Kadri? Sure! Do I think he 'oughtta be suspended?' Hell, no. He's a very good and physical hockey player.
Day to day physicality is part of the game - just like line play in football. There is holding on every play in the NFL; calling it is both a science and art, and officials try to establish limits and expectations. Same with hockey with the stick work, late finishes on checks, etc.
Trying to draw a line in hockey is about as sensible as drawing that same line for NFL linemen. They're not going to play nice. Every team has guys - or is desperately searching for guys - who will bring the nasty. Complaining about calls/non-calls misses the point entirely, which is that it doesn't matter until it radically shifts the outcome of a game (e.g., a clear offside that leads to an important goal or a pattern of calls that tilts the time of special teams).
TLDR: Part of playing hockey is getting hit.