Is it important to make sure I memorise all sections of the core - reading at SA level (or in particular for this SA) or some sections more likely to be examined than others? For earlier exams you could be asked to memorise long lists and sometimes REPRODUCE some sections of the core-reading verbatim, is it still the case?
Knowing the core reading inside out helped me a lot in SA2. I even made flashcards for myself as they weren't available through Acted at that time. The SA exams don't test core reading per se but you will need to know it really well not only to answer the questions but also in your professional life as a Fellow.
I would agree that knowledge of the core reading is VERY useful for SA5. there have been some questions where the answer has been lifted from the course, but more commonly the examiners solution will be build around the details of the core reading. The main difference between this and an earlier subject such as ST5 is that more than half the questions on each paper will simply be situations that the examiner has dreamt up from his / her experience. they will be related to the syllabus areas, but will not be linked to any particular piece of core reading. This makes SA exams harder, but you still need to know the details in order to do well in the questions that ARE based on core reading.
