I appreciate the responses. I'll take the advice into account. Regarding relative and absolute positioning however, I'd like to share a comment by Liz Castro:
Read her comment on the comments thread.
Fixed layout: yes, fixed layout has its detractors, but it looks great when done right, and that's what matters in certain types of books (not your 300-page novel). I actually like the format. If we are to reinvent the book, it will be thanks to this format. It has quite a lot of potential beyond illustrated books.
Susan: good question... but I don't know the answer....