Remember, If you gear all your qualifications towards being a pilot and it doesn't work out you don't have that much to fall back onto.
I have a BSc in Multimedia and IT Studies and am a qualified web designer/developer. Not my dream job but it's ok (I hate 9-5 and being stuck in an office) but I could handle this for the next 5 years and the money is good (Contractors get paid up to £600 a day and average .net developers get paid £45k pa).
Not doing an 'A' level in Maths / Physics due to the fact you aren't good at them is telling me your ATPL 's are going to be a stuggle.
Doing 3 'A' levels in Media Studies, PE and Art isn't not going to do you many favours on your CV when trying to get a job with BA, Maths and Physics will do a whole lot more.