6 weeks is plenty of time, just make sure you use it effectively.
When rewriting your notes definetely condense them with the vital information needed to get the grade you want in the exam and keep it in order with the specification.
I think it's a bit strange going from writing on notes to doing full papst papers, mabye slow down the transition, by doing this;
Weeks 1 and 2 - Rewriting notes.
Week 3 - Past Papers with notes and unlimited time (This is to gain some confidence and to learn structure)
Week 4 - Past papers with no notes and unlimited time.
Week 5 - Past papers in exam conditions
Week 6 - Prioritise and recap vital topics and read examiners reports.
People who say you need to revise months in advance to do well are wrong, i have a terrible long term memory so i revise close to exams.
In regards to the amount of time you should spend is spread of the topics with different weightings, don't spend 5 hours on something you know, as your doing A2, i presume, you should be doing around 8 - 10 hours per subject per week
Good luck.