Re-applicant to NYU Stern Part-time - need advice

In order..

1. I feel I know my weak areas - no extra-curriculars or major leadership experience or community service. Is it feasible to start on one or more of these now ? can something be done in 2 months before the 9/15 deadline ? I have decent GMAT score (690), ok GPA (3) and plenty of work experience. Actually I wonder if I have too much of it (means I am too old)
No. You can't do anything significant in 2 months. Delay your app. Focus on something that has long been a passion of yours. Try getting involved in it over the next few months. Make a connection of your recent activities with past ECs/hobbies and try to make it sound good. You really will not be able to show significant leadership experience in this in any case so no point fretting over it.

2. Should I take help from admission consultants ? can you recommend any particular consultant who is good with reapplications ? with Stern ?
some have free consultations, should i take them ?
Take the free consultations with an open mind of NOT necessarily engaging them afterwards. A decision to engage with any consultant should be because you really really need help and not because the free consultation was great. Some consultants offer a 'ding analysis' package. Such packages might be helpful for you to figure out if your perceived weaknesses in your apps were indeed the only weaknesses.

3. the ding letter says nothing about where the application was short. should i contact adcom or someone in admissions office ? will they entertain requests for reasons ?
Although schools in general do mention that they do not provide feedback, some of them do in fact give solid feedback. Tuck comes to mind immediately. Not sure about Stern. In any case, requesting a feedback after making it clear to them that Stern is your top choice this year, will not harm your app this year in any way. If you're lucky you might even get some good pointers.

4. can anybody share their experience with reapplication ? How did you handle it ?
I was a reapplicant this year in R1 having applied in R2 for Fall 2011 (waitlist then ding). Recognizing that I did not have enough time to do something radical, I chose to enhance the stronger points of my app and alleviate the relatively weaker aspects. The strong points were my work ex and international experience. The weaker points were my undergrad performance, ECs and quality of essays. I diversified my work profile consciously by getting involved in many 'business oriented' activities that were not part of my job responsibilities but which were in some way connected to my post-MBA goals. The idea was to highlight the fact that not only was I great at my regular job responsibilities, but I could stretch myself and excel even in additional responsibilities.. I couldn't do much about my undergrad performance so I didn't let that bog me down. As for ECs, I stepped up my involvement in the ECs I was involved in and ensured that I articulated them much better & weaved them properly into a coherent story. I consciously worked at improving my writing skills during this period and this resulted in a vastly improved set of essays compared to the previous year.

In summary, what I'm trying to say is that identifying your strengths & weaknesses is critical. As a reapplicant, we face a double whammy. On the one hand, schools have already seen our previous app and 'know' us better than first time applicants and as reapplicants we already have a sense of what is expected in the essays. On the other hand, we need to show a definite improvement in our candidacy. We not only have to alleviate the weaknesses but also improve our strengths lest the ad com think that we are resting on our laurels and not pushing ourselves. Hence it would be best if you don't rush your app. Take some time to think of what really are your strengths & weaknesses, take the time to work on them & polish them and then present your best application.

Good luck!