Sorry, but everything is important for Paper PM (it is no longer called F5). Approximately 50% of the exam is theory questions, and due to the format of the paper (with so many 2 mark questions) you can expect everything to be tested somewhere.
You can only be sure of passing if you study the entire syllabus. Also, if you are referring to chapters in our free lecture notes, then I hope you appreciate that they are only lecture notes and you need to watch the free lectures that go with them – it is in the lectures that I explain and expand on the notes. If you are not watching the lectures for any reason then you need to buy a Study Text from one of the ACCA approved publishers and study from there.