I was the exact opposite. In the first scene in the comic, Chase's dad is punching him for being a dumb jock, and not a science-dude like himself, and yet, he never looks remotely like a 'dumb jock,' so much (as you suggest), a slacker stoner. The text suggests he should look like a Fred, and he's drawn as a Shaggy.
I get that daddy Stein is an unreliable narrator and all that, but I had zero qualms with Chase actually looking like the text described him in the first time I encountered him.
Other changes, like the increased focus on the parents, or Molly being older (and Latina), were fine for me. But I kind of loathed the attempt to science-fy the Staff of One in the first season, and then the later season subverting that just felt weird and inconsistent. And I did love some of the parents actors. The Steins, the Minorus, Mama Dean, the Yorkes, the Wilders, all fun in their own way.