Hi getsunny,
First of all thanks a ton for taking out time to read and review my preparation plan !!!!
Your advice makes all the sense and I have already started implemeting it. I have added few lines against the feedback you have provided because there are few things that are still bothering me.
In all your advice has been immensely beneficial.
My thoughts on your thoughts

(elaborated them a little more, so that my case is better understood):
1) You should start giving full mocks. Since you haven't given a single full mock yet, you have no idea what your current level is. With 1 month to go, you need to practice full mocks to get in the habit of sitting through 4 hours of grueling GMAT test. Giving sectional tests is helpful for preparation and practice, but it doesn't prepare you for the mental fatigue that you face in the real GMAT.
Ideally, you should give at least 1 mock per week (full mock with all the 4 sections), then review the sections to identify your weak areas. Following this, you can spend the remaining week on fixing fundamental issues in your weak areas and solving questions. This way you will be able to progressively improve in the mocks that you give one by one.
Based on your advice I took a Quant CAT today itself. I knew the timing thing will surely come to bite me and it happened ! The timer stopped when I was still at the 27th question, adding to my misery as I was already struggling to get the correct answers in time. Even though I was frustrated, but completed the test. I know it was my first CAT , but I am heart-broken as I got 39.
What is your take on my score. Is there a scope for improvement. How much effort should it take. Any strategy you can suggest?2) The biggest mistake that you're making right now is doing difficult questions without mastering the OG content. It's good to practice difficult questions, but not at the expense of OG material. Remember, GMAT is an adaptive test and in order to get the difficult 700+ questions you have to get all the sub-700 level questions correct. Also OG material is unique and can't be replicated by any other prep company or personal question banks.
I would recommend that you finish OG question first and review each and every question that you got wrong. Understand where you're making mistakes and make a note of it. Then solve all the wrong questions once again to register every mistake in your mind. Once you've done with OG13, move to quants and verbal OG. Follow the same process with those books. Once you've mastered OG content and understood how GMAT traps the test takers, you will be able to perform well in the real GMAT.
I second your opinion that no prep material can imitate the OG questions. I should have mentioned this clearly, I did mention the percentage coverage of the OG questions for Quant. My bad !! The thing is - I have covered OG 13 quant completely approximately 2 months back. And believe me barring 5-7 questions (both in DS and PS each) , I found the questions to be easy and never struggled. I was so comfortable that I thought with a practice of some 700+ questions , I should be able to nail the Quant section( But again , as this was my initial phase of preparation, so I never timed myself.) So I shifted all my energies to Verbal section. Again on your advice I'll buy the OG Quantative review to get more practice on official questions.3) Getting a 750+ score is possible, but it requires a solid strategy. The ideal approach would be to develop a strategy for each question type and practice that. This should be the strategy that you would follow on each & every question within that type regardless of the difficulty level. For example, for Weaken questions in CR, you should have a strategy to solve the question everytime such a question appears.
Again no doubt in that - a score of 750+ needs a very sound strategy. Only reason I plunged myself into the habit of solving 700+ question was because I felt I can easily breeze through 600-650 level questions. I might be wrong but I still believe that about 90% of the OG questions are below 700 level.
Again the whole intent was to get good in the tough questions and safely touch the 50-51 level mark.Please suggest what's the best way forward now.
Thanks in advance and all the best with your preparation.