"Claims are not verified by W3C. Content providers are solely responsible for the use of these logos."

I do however think it IS possible and don't think that AAA is what most sites should be shooting for. I think that AAA would be better reserved as a target for sites that are specifically designed for use primarily by persons with different abilities.

Also it's possible for very some simple sites to comply to AAA because they don't nessicaraly have any diagrams or multimedia.

And as for good copy editing, well that depends on your audience but if your audience is a person who will befit by AAA then you should be writing in simple and clear way.