Divorce by mutual consent when wife leaves in USA

Hi, we got married in December 2009 when she was studying in US (after a short affair in 2006 and lots of hic-cups in between). Though I lost my sweet time after marriage only for her study, even could not plan for my future but she and her family never recognised me. Then she completed her study, returned India in April 2012 and joined a job here. As she left lucrative US career to return India because of me, she was much demanding, insulting me for her career sacrifice, was not cooperative for my job and social life, started completely contacting my parents and family. She just loved but never respected and listened to me/us and was no way supportive for planning a better future for both of us as per my affordability. These all resulted into misunderstanding and daily quarrel. We both could not just mange with each other and understand. We did not had physical relationship since last year. Then she manage opportunity in US, left last July 2014 and does not want to return at any cost. Now we want to conclude this with divorce. I have following few questions, will be obliged with help. 1. Does she need to come India for divorce procedure? (She does not want) 2. Can we get decree faster than specified timeline? 3. Marriage was registered in West Bengal; can I file for divorce in Mumbai? (I work in Mumbai) 4. How rigorous will be this process, how should I start proceeding?