Will they do justice to novel ? I hope they don’t cut important scenes from novel

They already cut off Koi calling his other siblings I do hope they won't cut of Grayson's and Dane's abuse

I think they also cut the part where Grayson was learning copying expressions from movies when the instructor told him that you could be a great actor like chase n then he denied sayin that i can only copy and can't improvise.

Or did this happened later in the novel?

I think that happens later on, I'm pretty sure that backflash shows up when Dane realizes how good Grayson was at mimics. I'm not too sure tho