Hi november22,

I think that you've asked some of these questions before; the advice that you're likely to receive won't change though.

Here is how you can adjust your plan to help you to better achieve your goal:

1) Trying to learn/practice/memorize all of the material BEFORE you take any CATs is a bad idea (it's also unrealistic).
2) CATs are great tools to help you measure your progress and discover your weak areas (so you can fix the weak areas sooner rather than later). You should plan to take CATs at regular intervals throughout your studies (1 CAT every 1-2 weeks, give or take).
3) Review (of the CATs, past work, old practice problems, etc.) is a BIG part of studying for the GMAT. You ask if you'll need to review 12 books worth of information (among other sources) after reading through the material just once? The answer is YES. Expect to review and plan for it.

A 750 on the GMAT requires an exceptional performance on your part. Unfortunately, there is no "perfect combination" of study materials that will guarantee you anything. The materials that you listed COULD be enough, if you do the necessary work to master all of the material. The GMAT is remarkably good at giving you the score that you EARN, so the better question is "what are YOU will to do to earn that score?"

GMAT assassins aren't born, they're made,
Rich

Since you already have the MGMAT guides, you might consider signing up for Beat The GMAT's free 60-Day Study Guide (https://www.beatthegmat.com/mba/gmat-guide). Over 40,000 Beat The GMAT students have already done so.
Each day, you'll receive an email with a series of learning activities that guide you, step-by-step, from Day 1 to test day. This will ensure that you will cover everything that the GMAT tests.

Here's an outline of all 60 emails: https://www.beatthegmat.com/mba/gmat-guide-outline

Cheers,
Brent