Don't worry too much about finding splits, since this technique doesn't work that often. I also found myself having to fully read all the answer choices, especially for long and hard sentences.
Analyze why you failed a problem: silly mistake? lack of vocabulary? fell in a trap? Do you use a logbook?
By the way, I never liked
MGMAT phrasing of problems in Verbal; I find they don't closely mimic the real thing. Maybe you got used to
MGMAT's phrasing, and hence aren't comfortable with the official phrasing?
I skyrocketed my Verbal performance by doing a bootcamp training with OG12 + OG Verbal, knocking down problems in sets of 30 each. At some point in time you'll start to pick up patterns in the problems.
I would suggest to first improve your CR, which in turn will also help your RC. Make sure you clearly identify the point, and don't fall for "out of scope" answers. Once you get the hang of it, CR and RC are a joke.
And do not underestimate the AWA

You Quant ability, makes you a good candidate for a 700+.
I'm glad it's over for me...