I am bookmarking questions that takes me longer than 2:30 to solve so I review then and find a more time-efficient strategy within 2 min.
That's only one possible way to deal with "too long" questions. The other is to learn how to cut yourself off efficiently and guess. (Don't make the mistake of thinking that you'll learn well enough that someday you won't need to guess. You'll still need to guess - the questions just keep getting harder!)
Go read the very first article I linked again (What the GMAT really tests). Then post again and explain to me why the quote above is only half of your story and why you will continue to struggle until you make the mindset switch that the goal is NOT the old school goal of getting everything right. :)
Then look at your analysis again and tell me what you need to change to "whatever, I'll just guess." Everybody has something like this on quant, but you told me you're going to get better at *everything*.
For NP, yes, they like to disguise these. Here are some things that can help you learn how they "think" in this area and you can use that to push your studies further.
http://www.manhattangmat.com/blog/index ... -gmatprep/For Word Problems are you getting hung up on the translation stage? Try these two articles:
http://www.manhattangmat.com/blog/index ... into-Math/https://www.manhattangmat.com/blog/inde ... them-real/Which ones should you bail on in this category?
You mention spending a lot of time on doing problems. What resources do you have that teach you how to get better at the problems? The OG explanations are almost never the best way to do the problem (plus the OG materials aren't designed to teach you HOW to get better).
What's the ratio of time spent doing vs. time spent reviewing?
If you spend 20 minutes doing a set of 10 problems, it should take you a minimum of an hour of review (afterwards) to thoroughly study those 10 problems. In many / most cases, it should be a lot longer than that. The review is where you actually learn how to get better and includes all study activities such as looking up alternate solutions (OG Archer, online forums, etc), looking things up in content books that teach you what you need to know, making flashcards, figuring out why you made a certain kind of error and how you could minimize the chances of repeating that error in future, doing drills when you discover weak skill areas, etc.
Go back to the 2nd article I posted, the "2nd level" of GMAT study, and look at the how to learn section.