I like the idea! Sort of a read-along thing. 
You could always let people respond/comment in the same thread, so it's more interactive and also clear it's sort of a 'rough draft'? And it would be easier that way to read chapters and then only the comments relating to those chapters afterward, without 'spoilers' so to speak. Like a Let's Play! Except, a Let's Read. Those are just suggestions and hardly the law of the land, though; it's up to you how you're comfortable doing it. I'd have no problem with that, I don't recall if users can delete their own threads but if not I can delete it when you're done.
You could always let people respond/comment in the same thread, so it's more interactive and also clear it's sort of a 'rough draft'? And it would be easier that way to read chapters and then only the comments relating to those chapters afterward, without 'spoilers' so to speak. Like a Let's Play! Except, a Let's Read. Those are just suggestions and hardly the law of the land, though; it's up to you how you're comfortable doing it. I'd have no problem with that, I don't recall if users can delete their own threads but if not I can delete it when you're done.