Should I be aiming higher?

Actually, I see the confusion. My apologies, what I meant but failed to say that it is mathematically possible to get an A* with a B at AS ]

Wait no actually :L please tell me if I am wrong (as my maths is shabby) that above 70% in AS combined with above 90% in A2 fulfils the requirement of 80% overall and 90% in A2 for an A* overall?
Are we just saying the same thing but in different ways?]

That's correct but you don't need above 70% at AS. You could get below 70% in AS but then above 90% in A2 and come out with an A*, up to a limit of no lower than 60% in AS as at that point you would need 100% at A2.

No:

http://www.rewardinglearning.org.uk/accreditation/guidance/gce_developments.asp

Don't post with such authority if you don't know for certain.

Actually, in terms of when I went through I am right. My friend got 78% and 80% in his AS whilst achieving 100% in both his A2 exams and only achieved an A. And this was not just an inconsistency because there are a number of people in my year who were in the same boat. I know this for certain as I saw his results sheet and our teachers all had a letter from CCEA detailing that you needed 80% in your AS and 90% in your A2.
I am not arguing about this years boundaries or for AQA but for the year I went through as I have seen people just miss out.

The CCEA says otherwise, but regardless, you made out that this is for all boards which is incorrect.