First, your prep is not about how many questions you do or how many tests you take. It's about how effectively you're studying. :)
Second, look at the list of test scores you gave me - are those accurate? You listed three scores in the high 600s but one in the low 500s. Unless that was your very first test, that's concerning - why did your score drop so much on that test?
Next, what have you been using to prepare so far? How have you been studying? Read this:
http://www.manhattangmat.com/blog/index ... -the-gmat/Have you been studying in the way that article describes? Analyze a practice CAT thoroughly and use that to set up a several-week study plan. Analyze every problem thoroughly (spend way more time analyzing afterwards than you spent doing it in the first place). Learn how to decode test questions. Learn more efficient solution methods. Learn how to make educated guesses. Learn how to modify your bad habits to minimize careless mistakes. Etc.
If you haven't been studying in this way, then you're going to have to go back over a lot of the previous work that you did, because you didn't get as much out of those questions as you could / should have.
Also, read this:
https://www.manhattangmat.com/blog/inde ... lly-tests/Does that reflect your overall study approach? Or has your study approach been a more school-based approach? You won't get to a 740 with a school-based approach (as described in that article).
Read the above (and follow the links to other articles), then use the below to analyze your most recent MGMAT CAT(s):
http://www.manhattangmat.com/blog/index ... ice-tests/Then come back here and tell us the results of your analysis and what you think your plan needs to be based on all of that. We'll tell you whether we agree and advise you further. (Note: do share an analysis with us, not just the raw data. Part of getting better is developing your ability to analyze your results - figure out what they mean and what you think you should do about them!)
Also, I can't tell you whether 9 weeks will be enough time - it might be, but a 740 is a really high score. It's going to depend on what I hear from you after your analysis, and also whether you typed that 530 score correctly and, if so, why your score dropped so much on that test.
Oh, and on your question about buying more practice CATs, we only have one set - you can't buy more. When you buy access to the CATs, you can continue to take them for as long as you want. The first 6 tests are guaranteed not to contain any questions that you've seen before. The tests after that may have repeated questions.
For your CR question, as long as that approach isn't killing your performance, that's great - go for it. It might be the case that you were taking too much time to take full notes, writing down things that ultimately didn't matter.