Hi Anton,
Based on your analysis of this CAT, your biggest 'issue' is the little things that you are not doing to make sure that you get the correct answer. There are only 31 questions in the Quant section - and you cannot 'absorb' 5 little mistakes and still score 700+. What additional work should you have done (on your PAD, not "in your head") to make sure that you got those questions correct? If you have not already done so, then I suggest that you redo all of those questions, by head, step-by-step on your pad. To maximize your performance on Test Day, you cannot leave these little details to chance.
With those 6 Verbal questions that you narrowed down but still got wrong - you were really close to getting the correct answer... so what did you 'miss?' Was it a grammar rule or some specific wording in the prompt? Do you know what the rule/pattern is now, so that you can spot it again later (if/when it shows up on a different question)? Could you have approached the question differently and gotten the correct answer? What notes are you willing to take to be sure that you're getting the correct answer?
One of the reasons why Business Schools put so much value on an Applicant's GMAT Score is because the GMAT will always give you the Score that you EARN. Right now, I think that you have the capacity to Score in the high-600s or 700s, but you're not consistently doing the necessary work to earn all of those correct answers (and by extension, that higher result).
GMAT assassins aren't born, they're made,
Rich