get everything in writing. keep every correspondence. get her to send you emails, letters, indicating the threats or harrassment. one day your going to have to prove your case. if you apply for her gc and you write to the USCIS about her then they might go after you and put you in jail b/c you are the citizen and it will appear that you took money for GC and now that she's full of issues you don't want to deliver on the deal. just remember that they don't know your story or cultural background so your going to have to prove that she was threathening you to get the gc and you had no choice b/c of your parents in india, but you really don't want to get her a gc.
i don't know anything abt the dowry laws in india, but maybe if you get the intention to use dowry (eg. an email where she says she's going to do it while you clearly state that you haven't taken any money from her family) can probably be used in court. maybe you could countersue her.
if you bring her here, she can file for alimony and it seems her family is pretty smart abt all these things and would have thought abt this already. your going to be stuck with this. maybe you could get her to sign a pre-nuptual before registering the marriage. if you don't then she will not only get alimony but half of your estate (property, assets, everything and anything).
best thing is proceed with care. consult with another attorney who is well-versed with these issues and get everything in writing or recorded (mybe you could even get your phone conversations recorded. (eg. talk to her on speaker phone and hold a tape near the speaker).
you will need to prove your case, either here or in india.
