So basically my chances of A* is very low? Do you think it will be better to repeat the AS levels too? BTW, I believe that I scored 110, and according to the threshold it is 101.Yes that combination is possible. Don't worry about that.
So the thing you wanted was this P1 and P3 covers 60% and S1 and M1 covers 40% of total 100% of paper 9709 A level Mathematics :¬
P1 and P3 60% (30% + 30%)
S1 and M1 40% (20% + 20%)
S2 has 20% as well so it wont have any effect if you change it to S2.
Congratulations if you scored an A in As level Mathematics. So the thing I will like to tell you is you don't need to worry about this thresholds you just have to prepare at best that's all you have to do and pray for now and wait till the results are released. Answering your question you should score over 225 outta 250 to reach to the A* and that's the minimum score so if you say that you scored 101 in your As level so for now you need to score 124 of 125 to get an A* and every good universities need a grade B except top 20. So don't worry about that even if you scored 90 in your A level you will get selected in any good university below the 20 rank. I wish you can score A* or at least A but hope for B as we heard that, "Never expect high as if you failed you will be demoralized, always expect low so that if you failed that you wont be hurt much." If you are really in search of A* or A and may not God grant you B if so then must repeat your examinations in June '15 session. Rest up to you as there is no age limits out there.
All the best.