You must file the petition in the US, unless you are residing yourself in India. The F-2A category (Green card petitioner) is backlogged only to September 2013 for India, so I would recommend filing it as a green card holder no. for the quickest result.
If you have been counted against the cap within the past 6 years, then you should not be cap-subject on a new petition. You face several challenges, however, given the history described in your inquiry. Consult with an experienced immigration attorney.
Yes. A person who is out of status, but entered the US lawfully, may seek adjustment of status on the basis of the petition of a US Citizen spouse. Please consult with an attorney for more information.