Hi.
1- As regarding the activation, It happens that I know already what I need to know and therefore extract from the book. Great! So go about extracting it. Once you've photoread and incubated the book, form your mind-probing questions and then superread and dip for what you need. Since you know what you need, your sense of purpose will be more well-defined.
2- Most topics i am doing require full conscous comprehantion and not just the big picture like calculating the current in a circuit, or solving a differential equation.
You still activate in the normal way. In fact, you use more activation layers to push comprehension up. You may wish to take a look at AlexK's experiment, as it very clearly illustrates the activation process, and the importance of activating in layers. Here it is: http://www.learningstrategies.com/forum/ubb/Forum8/HTML/002346.html
Also, since you brought up mathematical situations, I suppose you will be dealing with problems like these. You will need to practise problems. Photoreading will speed up the time you need to learn the basic concepts and formulae. Also, you may find that when you do problems, the solutions come more easily. A short discussion on mind-mapping and how it may be used to help push comprehension up may be found here: http://www.learningstrategies.com/forum/ubb/Forum8/HTML/002668.html
Wouldn't it be worthed to rapid read multiple times directly to the sections of the pages where that information is?
Superreading will help you locate the information more quickly, and I find that superreading a few times takes the same amount of time as just reading it once. Plus, it gives higher familiarity and comprehension. If you wish to do so, then you can rapid read AFTER you have superread the texts. You'll find that it will fit together much more easily and quickly.
Also, to help mind probing, would it be wise to make a written list of things I need to know from a book and sort of reminding myself of them during the day like for example when showering, driving before sleeping etc? How would that effect the activation process.
You may mind probe during the postview and also just before you begin your activation sessions. In between, I think it would be best to let it incubate. You can think about the questions from time to time, but don't force it or make it an issue. Also, don't expect a sudden rush of answers during the mind-probe. This can and does happen during spontaneous activation, but not always, so don't worry.
Hope this helps.
KWLee