While not putting all ones eggs into one basket is a good idea there is also the concept of speading oneself too thin. That is having too many purposes without a clear focus on one.
Generally for photoreading any will do. It's with the activation that you need to determine exactly what you're doing. If you decide to activate for pleasure and school are only only focused on the pleasure aspect or need for school? Typically I advise to have one clear purpose remembering that a book you have already photoread can be returned to later for the 'other' purposes as they arise.
On a deeper level you'll probably cover all those aspects anyway its bringing it to the conscious level to the degree that you desire and need that is really you "current" purpose. The resources are there and at an other than conscious level you can still be influenced by someones writing style. When you think about it... it's what draws you towards enjoying certain kinds of books, makes comprehension easier if you have an affinity for the style and make activation faster.
Alex
