A* in Politics and Maths.

No idea about politics, maths in general is all about doing as many practice problems as you can, timed past papers, etc, etc.

Yes, for maths, I’m doing it in one year, does my plan sound realistic or optimistic:

Complete Pure 1 by end of Nov
Complete Mech&Stats 1 by early Jan
Complete Pure 2 by mid Feb
Complete Mech&Stats by end March

Also, should I take notes, or just practice practice practice?

Yes, for maths, I’m doing it in one year, does my plan sound realistic or optimistic:

Complete Pure 1 by end of Nov
Complete Mech&Stats 1 by early Jan
Complete Pure 2 by mid Feb
Complete Mech&Stats by end March

Also, should I take notes, or just practice practice practice?

Likely unrealistic, you will have exams which you will need to revise for ( as they will matter for what your teachers think for you, in turn, your reference along with the prediction. Additionally, it would not be recommended to do this, the jump from A1-A2 may be too quick - A2 maths is ALOT harder and a lot more fundamental knowledge is needed. Therefore, you will need to have made sure you are SOLID with AS, completely solid having done almost all types of exam questions before moving on. As you may find yourself progressing in terms of what chapter you are on, but not so much in your mathematical skill. I would say AS pure and M+S also 1/2 of pure 2.