Hi Nielgmat.
To score V40, you need to get around 80 percent or a little more of the counted verbal questions you see correct.
If you're scoring at that level, you'll see only medium and hard questions on the verbal section of your GMAT. So, you need to get 80 percent of 600-700- and 700-level questions correct.
However, that 80 percent does not apply evenly across the board. Ideally, you'd get 100 percent of the medium questions correct. Then, you'd get 80 to 90 percent of the medium-hard questions correct, and enough hard questions correct to get to 80 percent correct overall.
So, we could say that, to score V40+, you need to get close to 100 percent of 600 - 700-level questions correct, 80 to 90 percent of the easier 700-level questions correct, and perhaps 60 percent of harder 700-level questions correct when you are practicing with individual questions, though to be safe, I think you should get at least 70 percent of 700-level questions correct, at least if you are doing them untimed.
Regarding the time per RC question, around two minutes per question including time spent reading the passage would be great.
That said, your best move is to do much of your practice UNTIMED and shoot for close to 100 percent accuracy untimed. Then, once you're getting the questions correct virtually all the time, you can work on reducing the time per question until you're answering them at test pace.
For some tips on how to practice for GMAT for best results, see this post.
The Best GMAT Practice Methods