I'm sorry that you're having such a hard time with CR and RC. You mention score fluctuations and timing issues. It's entirely possible that you are fully capable of scoring at the top end of your current range
as long as you don't mess up the timing. If that's the case, and if the higher end of that range is an acceptable score to you, then your real goal here is to fix your timing (and, by extension, your decision-making), not to try to get even better at individual questions.
You've mentioned reading my RC articles, so I'm guessing you've also read others, maybe even the ones I reference below. But I still want you to go through this analysis process - re-reading these article if you've already read them.
One of your tasks is to make it to the verbal section with enough mental energy left in your brain to get all the way through that section. This requires you to make certain decisions in earlier sections (especially quant and IR) to make sure that you're not using up too much mental energy before you even start verbal. Next, you still need to continue to make good decisions as you get into verbal, because you're still expending mental energy! Do too much in the first half of the test, and you'll crash and burn before the section is over.
Read (or re-read) these two articles:
http://tinyurl.com/executivereasoninghttp://tinyurl.com/2ndlevelofgmatThink about how what you've been doing does and doesn't match up with that and how you may need to change your approach accordingly. The first one is more about the decision-making stuff that I referenced above. The second one is more about how well prepared you are to answer the questions that you do answer, although it includes the component of knowing how to tell that you should let a particular question go (before you've spent too much time and/or mental energy on it!).
Then, use the below to analyze your most recent MGMAT CATs (this should take you a minimum of 1 hour):
http://tinyurl.com/analyzeyourcatsBased on all of that, figure out your strengths and weaknesses as well as any ideas you have for what you think you should do. Then come back here and tell us; we'll tell you whether we agree and advise you further. (Note: do share an analysis with us, not just the raw data. Your analysis should include a discussion of your buckets - you'll understand what that means when you read the last article. Part of getting better is developing your ability to analyze your results - figure out what they mean and what you think you should do about them!)
You can do this for just verbal or for quant and verbal - your choice. And try one thing for me: if you could (retroactively) pick 4 questions in the verbal section to just not do at all, which ones would they be? Why? How much time would you have saved? (Assume you take ~20-30 seconds to decide to bail, so time saved is after that.) How much mental energy (relatively speaking) did you expend on these things? How many careless mistakes did you make elsewhere? Did those mistakes come in clusters anywhere in the test?
Oh, and the work you're doing to read regularly is valuable; keep that up!