Hi Moghli,
Sorry I am only noticing this post just now! I have no idea about cancelling the original I-130 and starting again in Delhi, but our experience was pretty straightforward:
Filed on Feb. 6th, it was approved and sent to Chennai on Feb. 13th. I don't know if we just got lucky, but it was only a week! To speed up the process, you could complete the DS 230 Parts I and II, and the DS 2001 and have it ready to mail fast. Keep in email touch with Chennai (send an email about a week after you file I-130) and they can email your case number faster than the mail takes (which is about 10 days from Chennai to B-lore) and you can submit the Packet 3 docs. right away. (Packet 3 are just the DS docs mentioned previously.)
Give the Chennai consulate another week, and then email asking for the Interview date, keeping in mind that the faster you get Packet 3 back, the earlier the interview. (Or so I am guessing.) (We got our interview date on March 5th via email, it was another week to 12 days to get the website posting and the actual interview letter.)
Soooo... The only problems that could arise are the amount of time you have been here in India. Check the Delhi website for more details, it MIGHT be helpful to try and call or email them, but I am not sure how responsive they are! Search this site (maybe in South Asia forum as well as DCF) for people who are of Indian origin and how they worked the residency issues - I vaguely remember people doing this who had not quite been here for the regular time frame, just be careful as the postings may be old and USCIS has changed the time requirements fairly recently. (Within the last year or so!)
http://newdelhi.usembassy.gov/uscisi130pet.htmlIn the meantime, make sure you have all the docs ready for an Immigrant Visa - a little bit different than the K3 visa. The benefit of doing this is that the CR1/IR1 allows your wife to work immediately, AOS is not required, and getting a DL for your state is generally MUCH easier!
Good luck, keep us posted on what you decide and how things go!