Hate the Casting...
But you already knew one of these posts was coming didn't you?
Larry Underwood was a white man, sorry to break it to you. As they say "Another tick for the ethnic diversity box"! & make a white character black. The whole dynamic between him Nadine & Lucy would be drastically different. Debate me if you must but it is the truth. Harold Lauder seems to be a rather thin man now. Nick Andros looks like a biker not the timid self reserved man he was in the books. Marsden as Stu Redman is doable, actually he's a more inspired choice than Gary Sinise was in the older mini series. Yes I know you're all shocked but I think so anyway.
Now Amber Heard I DO like as Nadine, although she would've made a great Julie Lawry too IMO. As for Flagg, I would've liked a more inspired choice than Skarsgård. Nothing against him but even a unknown would've done nicely provided you actually took the time & effort to find your Flagg rather than just shop for the biggest name(s) around.
WTH man? Yes I understand you can duplicate the book exactly but at least try to honor the source material with some semblance of common sense in your casting choices.