Frustated & dejected with 1st GMATPrep Mock CAT

Hello GMAT brothers and sisters ,

I belong to the IT male group (non-native English speaker) (so called highly competitive, I would say unfortunate ) where only a score of 700+ in GMAT would only suffice for admissions.

I had given my first shot at GMAT in Oct end and received a 620 (q39 35). After reading a few inspirational stories abt how test-takers have a chance for comeback, I was inspired to put my heart & soul into the preparation. After taking leave from work, i blasted thorough the following books for 2 months.

GMAT 12th Ed.
Manhattan Guides (All sets of Quants & SC)
CR Bible

To get into the groove of answering tough Maths questions, I had also enrolled into GMATClub tests.

As i was consistently getting around 10-13 questions incorrect in each of the tests (apart from 2-3 insanely difficult tests ), I was getting the confidence to tackle Maths and set to face my 1st GMATPrep test (reinstalled).

(I couldn't find the exact source, but I was told earlier that the above hit/miss ratio is sufice for a score > 48)

When i finished through the test, I was pretty satisfied with my performance, but that satisfaction lasted only till I clicked the <Next> button.
Score of 650 (q46 v34)
But the most baffling part is I had got 12 incorrect in quants and 12 in english. Dejected and frustated as mentioned in the title thread, I have a few questions to the masters & experts in GMAT.
What should be the ideal hit/miss ration in GMAT? From the score i got it, it seems as if only 5 incorrect answers in each of the section should be made to get a score 700+?
It does seem to me that experimental questions would have also played a part in this score, but as bb had pointed out in a thread, we do not have much control over it. Would that mean luck plays a major part in GMAT?

Thanks in advance

P.S. I have completed 16 of the 25 GMATClub tests and have reviewed only the first 8 of them.