The way the computer adaptive test works, no one can say what subjects you will see. You might see 4-5 combination and permutation problems or none.
I'm not sure why you are targeting specifically 43-45 as a score, but that would put you in the mid-70s, meaning you would have to outperform three out of four people who take the test. It's hard to imagine being sure of doing that by ignoring so many topics that you know are covered on the test. I have found that you can do grouping formulas instead of Venn diagrams, but there are really no alternatives to the other topics.
You can certainly try taking practice tests without having studied those topics and see where it gets you., but remember, the subject profile you see in any given practice test may be totally unlike what you get on test day.
My advice would always be to study as many topics as possible, focusing, of course, on mastering the most basic ones first. I am simply uncomfortable with ignoring subjects that you know are significant portions of the test. Remember, these are topics that the test-makers recognize as relevant to your MBA studies.
Tani Wolff