Use them in whatever way helps you the most. The test banks will help you identify where your weaknesses lie, giving you topics to focus your time on instead of reviewing material you're already very strong on (which you should still do, but this shouldn't be an equal amount of time as the areas you struggle with). As you go through, take notes of the ones you know very well, kinda well, a little, or not at all.
If it works for you to go through each topic with the individual materials, do that. If it works better for you to do one source completely, then another, then another, do that. The most important thing: Don't learn the questions, learn the fundamentals and use the questions to understand how those fundamentals are likely to be assessed
Studying for the MCAT is a highly subjective and personalized approach. Everyone will give you different answers, but figure out what helps you retain the material the best. Practice exams can give you a fairly realistic idea of how much you are retaining. Personally, I struggle with repeatedly taking practice questions, since they don't help me understand the concepts, and it's impossible to run into every single possible MCAT question through repetition. If you find that you are using them all and still not retaining the concepts, look for other resources to augment, such as YouTube or Khan Academy videos.