How much time do you spend reviewing the questions each day?
I've been starting sometime between 7 am and 8 am and working on nothing but until about noon. I try to keep FA right beside me with a couple other books, and will annotate anything that seems significant into FA, and if I'm really unsure look it up in another book. I don't look up details to every question though, since I'm getting a good knowledge base built I feel and that helps move faster. I can do about 30 questions + explainations/hour now. I have also tried to do a last question set of the day, like 20 - 30 questions at night after I'm sick of reading, and that usually caps 100+ questions.
I've heard from enough people to not worry over your percentage score on QBank. Use it to learn from (same with any other question source). I might not feel completely comfortable with a subject before I start questions on it. I may only read the FA chapter before doing those, for instance. That way I am reading and doing questions at the same time, and I've found when I've seen a question on something I later read about, the reading sticks better. That's not to say you shouldn't try your best with QBank or anything else, though. I get great practice at pure test-taking skills with it, too. My scores have gone up greatly from slowing down and taking a little more time per question to think through ruling out wrong answers. Learning how to do an effective ruling out of an answer choice will help immensely with questions where you might not know the answer straight off. Don't just try to find the right answer,
be very deliberate about why others are NOT the answer!
Now with the whole not-caring-about-your-score thing, thats my learning style. I need to be far more active, which is why I need to jump in a lot earlier. For some people, they can read for 5 hours and retain it all. I might keep only 30 minutes if it's say, biochem or behavioral

But when I do questions, they force me to be more engaged and I don't lose focus as easily. I think the better strategy is to worry about NBME tests and the released items scores, as they are the real predictors of your performance.