Thanks for the tip about exporting a Word document to HTML and submitting that. It saves a whole lot of time.
From the looks of it (and a nice reader who sent me an email), the submission of Chapter 3 went well. It seems like that only thing that went missing was the lines in between sections. I've just submitted an edited version of Chapter 3 with the lines (I hope).
Chapter 4 will be in the queue shortly as well.
Edit: Initially I was thinking of adding some things to chapter 5 and 6, but I just read through the chapters and think everything is fine the way it is. I'll leave those parts to a continuation in the future instead!
Thanks for all the emails I've received!