Practicing number theory and DS questions is a good idea regardless of quantatative background, in my opinion. Really, you should practice all aspects of quant regardless of your background. I scored pretty well in math when I started taking practice exams, but I'm glad that I practiced it the whole way through. I think that seeing how the GMAT writers present the questions and keeping this fresh in your mind can be very helpful.
It looks like you have a lot of material for verbal. For SC, I recommend going to the resources section of this site and looking at Spidey's and/or Sahlil's Grammar notes, in addition to the Manhattan guide (which is good for overview and fundamentals). This site's flash cards are useful too (for everything, not just for SC). Make sure you understand why each wrong answer is wrong and each right answer is right. Another tip is to review what you (and others) type. See if you can find any errors that break SC rules. It's annoying at first, but I think this process was good practice and helped to show me some grammatical errors that didn't instantly click in my mind as incorrect. Also, scrutinizing your own typing will be helpful for AWA.
Learning the critical reasoning types and the common types of wrong and write answers for each type of question is the best way to go for CR. Then practice, practice practice. I had studied for the LSATs (even though I ended up not taking that exam), and that helped me a lot with GMAT CR.
Having a good memory is a good thing, in general. I had couldn't use the OG books more than once either (other than for review), but a good memory should help you to learn and remember the SC rules. Also, a good memory is helpful for remembering where a certain piece of information was in an RC paragraph.
Use the prep books for the areas that you feel you need to strengthen the fundamentals, but make OG the core of your studying. I liked to time every question (and do sets of 10-30 questions at a time). Then I'd look at how much time I took. Even if I got a question right, it was still nice to know where I got hung up on. Knowing how to do something quickly and right is different than just knowing how to do something right. So just because you know how to do a question, doesn't mean you're done learning. If a certain question type tends to take you 2:30, 3:00 during OG, you want to practice them even if you always end up getting that type of question right.
