First, Congratulations on a great score. It is admirable of you to keep working to improve.

To answer your questions:

The AWA is scored separately from the rest of your exam - you will get a score from 0 - 6 on each essay. This does not get factored into your total score and remains separate. For most schools the AWA is not a very important piece of the puzzle but you want to try to score at least a 4. The graders are looking for a well organized essay that has few gramatical mistakes and clearly answers the question. The form of the question is different for each essay - one asks for your opinion and one asks you to evaluate the logic of a statement.

As far as improving Data Sufficiency, it is likely that you are falling into typical traps of reasoning set for students who are not thinking the problem completely through, in your case becuase of time constraints. It would be most helpful to review the specific questions you have missed to see if you were falling into traps and what they are so you can avoid them in the future. That said, many people score very well on this test adn still miss questions - it is not a point based grading structure and is designed to get harder and harder until you start missing questions so with a 47 Quant I wouldn't worry too much.

IN Sentence Correction it seems you may do well to review the 6 - 8 basic rules that are most commonly tested and make sure you understand how to spot them on the exam. get used to comparing answer choices in order to make decisions instead of editing sentences first and then trying to find a match to your edits.

Hope that helps.