Okay, you're starting to answer your own questions re: why you're making the mistakes you're making.
1) Your timing isn't good enough yet, causing you to rush at times, and that causes careless mistakes. Fix the timing, that eliminate the rushing. That won't eliminate ALL careless mistakes, but it'll eliminate the ones that are due to rushing. :)
Read these and start doing what they describe:
http://www.manhattangmat.com/blog/index ... to-win-it/http://www.manhattangmat.com/blog/index ... nt-part-1/2) Under pressure, you lose your process. There are a few reasons this may be happening. The timing pressure may cause you to feel that you need to abandon your normal process and speed up. You may also be feeling mental fatigue and simply stop being as systematic as you know you need to be - particularly for verbal, as it's the last section. You may also be fine applying the process for 5 or 10 questions but then lose that on the 15th or 20th as your timing starts to "go off" and you start getting mentally fatigued.
So one thing you might want to do is examine your strategies to see whether you can streamline them at all. Keep all necessary steps, but if you can combine two or drop unnecessary steps, then do so.
The next thing is to use written, visual cues to help you make sure that you're being systematic on every problem. I suspect that the timing pressure plays into this as well and, once you fix that, you won't feel the need to rush and drop steps of your process. Once you start dropping steps / being less systematic, it's hard to make yourself start again.
For example, you mention CR. For CR, the first thing I write down is a one or two letter abbreviation for the question type - ALWAYS,
every single time. This makes me figure out what the question type is, because I can't write it down till I know, right? So I can't skip the step, because I can feel that something's wrong already if the first thing I write down is NOT that one or two letter abbreviation.
My next step is to take light notes on the argument and, if it's a type that has a conclusion, to note the conclusion. Again, I've got to write that down. My third step is to remind myself what I'm solving for / trying to do on this type of question. For that, I go back and underline my question-type abbreviation (again, a visual cue / reminder) and then I underline anything important in the argument based on that Q type. (eg, if it's one of the assumption family questions and I jotted down an assumption that I brainstormed, I underline that assumption. I also underline the conclusion, because all assumption family questions rely on the conclusion somehow.)
And, finally, when I'm going through my answers, I have ABCDE and I know that I need a symbol next to each one of those letters. (Symbols can mean: this one's wrong, maybe this is it, I don't understand this answer, and this is the one I want to pick.) Again, if I don't have a symbol next to each answer, something's wrong - I'm not being systematic.
Now, you don't need to do things exactly the way I do, but you do need to have your own consistent process that you follow. Every. Single. Time. Did you discover that you just didn't do it on two of the questions in that 10-question set you just did. Make yourself go back and write everything out exactly the way you should have. That's your "punishment." Do that enough times and you'll start remembering to do it the first time around so that you don't have to go through the tedious work of writing it out later. :)
For 40+ verbal, getting around 80% of the questions right on GMATPrep sounds about right, yes (though it could be fewer as well). 40 is the 90th percentile.