I think you need to find a rate that is comfortable to you. I found that I was going too slowly and that speeding up improved my results.
Having said that, Paul set times for each of the process steps to keep you moving along. The danger of going too slowly is that you'll begin to focus on the words on the page, or that you'll get bored/frustrated/annoyed, or that you'll spend your time worrying about what you're doing instead of relaxing and playing with it. Pay attention for signals that you've "got it" and then move to the next page.
My gaze used to drift up also. It was most pronounced when I used to burn a hole in the spine of the book in an effort to see the blip page. When I relaxed and opened my gaze to notice the outer edges of the pages, I got the blip page and my gaze remained more stable.
