Since you mentioned my name, I guess I should answer it
First, I am not a guru... I just learn from my own explanations and the explanations of other memebers here
Second, I bombed my verbal first time (24)

I really don't want to do it again
Third, I SUCK at RC and I am in no way can help you there yet.
Fourth, I think your SC hit rate is pretty close to mine, so I don't feel comfortable to give you advice on this... just buy
MGMAT SC book and sleep with it for the rest of the coming days before you GMAT

this is what I am doing, literally... that freaking book is always within the reach at the moment.
Fifth, your materials/books are just fine, adding
MGMAT SC to those is a MUST... no matter your 80% hit rate
because of the above points, I think I was in your verbal boat just a couple of months ago... my verbal can widely fluctuate due to RC, but I saw it going up recently because I am clearly focusing on it.
My best advice to you would be regarding improvement of CR. And the only way to do this is to PRACTICE... the MORE the BETTER... no other way unless you are a genius or a native speaker with good verbal skills and logic.
Try CR 1000.. that document is a sticky here in the Verbal forum... it has LSAT questions that are more difficult.
I used to HATE CR so much that I was scared to see one when it appeared on the screen, but now I LOVE to tear those apart... that is FUN! in the end the logic becomes clear....
so here is u2lover's plan to improve CR:
1) understand the parts of the argument and be able to differentiate premises and conclusions
2) create a frame in your mind, which argument exists in... that frame is the boundary
3) identify OUT OF BOUNDARY answers
4) pick the most obvious answer when it comes to INFERENCE or ASSUMPTION
5) read the explanation to EVERY answer choice and understand why EACH is correct or wrong
6) beware of traps... EXCEPT, STRENGTHEN vs. WEAKEN, etc.
Trust me... practice is the key in CR... I can in no way help you except by telling you what I did to not be afraid of CR and be comfortable with it.