I do A-Level Art, and I am predicted an A*.
I believe that if you wish to do Art at a high grade (A-A*) then there is only so much hard work, reading around, researching, practising etc. you can do. When it comes down to it, you need to have a natural flair and talent to achieve the top grade. This isn't, of course, a written law. You would certainly be able to do Art, there is much more variety of techniques and styles you can use (3D is an option too), so you can avoid dodgy areas of your skillset.