You need standard text-books, relevant study-material and newspapers/magazines to effectively cover the syllabus. With this you develop clarity and logical thinking develops.
What all you are doing is for a purpose and if you follow the ‘take care of basics and the details will fall in place’ principle; you will be able to manage it well.
As it used to be wide-intensive for Preliminary Examination and selective-extensive study-plan for Main Examination, the changing trend necessitates knowledge and awareness relevant to the real world
and information ‘a mile wide and an inch deep’ comforts in handling question papers efficiently.
It is practically impossible to master each and everything under the sun but, knowing a little about as many things as possible brightens your prospects.