Aaravika,
Based on my personal experience in 2012 September, and being in a similar position as yourself, here's what I found out in response to your questions:
1) I plan to submit all documents required for court marriage on Dec 7 , is his presence compulsory for it?
My Response: No, his presence is not required to submit the documents for notice of intended marriage, but you will need copies of his passport to submit as supporting documents. I had also submitted them alone at BKC Marriage Registrar.
Caution: The registrar will accept the notice of intended marriage from you, however, she will insist that she has to verify his original passport authenticity. You obviously cannot show his original when you are giving notice alone, so to workaround that issue, make sure you have a 2 working day time from the day he lands to the date of your court marriage. That way, you can go there the day before scheduled court marriage and get his documents authenticated, without facing issues on the day of the court marriage.
2) I am planing for a court marriage on Jan 8, is registration still required?
My Response: I believe for marriage under Hindu Marriage Act, 30 days notice is compulsory. If you are going for visa for US, you need to have a marriage registered and get the marriage certificate.
3) Is it true that if we do a court marriage on Jan 8 and get it registered on Jan 10, our marriage certificate will be received within a week of court marriage?
My Response: If you go by the official procedure yes, you are supposed to get your certificate 7-10 days after court marriage. HOWEVER, I got it on the same day, within about 25 mins. How? I went through an advocate who charged me Rs.5,000/- for assisting with notice of intended marriage, the actual day of court marriage, and an additional Rs.500/- for getting the certificate on the same day.
They accept bribes at the registrar, and sad as it is, that is the way the government machinery works: if you try to go by the book being honest and straight, you will be visiting them for weeks / months without a solution, unless you pay them a bribe.
4) Can we take US visa appointment date without marriage certificate being in hand?
My Response: YEs you can. When filling the application, put your status as spouse. As long as you have the marriage certificate in hand on the day of the visa interview, you are fine. Thats how I did it too. My court marriage was on 17th, and visa interview on 20th.
5) We wish to fly back together, please suggest us the best possible way in the time lines as specified above, that we can fly back together on Feb 1, 2014.
My Response: The earliest possible date that you can schedule the court marriage after he arrives, please do so: AFTER leaving two Weekdays (Mon-Fri) to authenticate his original passport prior to court marriage. If you can find an advocate who assures you to assist getting the marriage certificate the same day, then schedule your visa interview 2-3 days after you are married. If you are having a ceremonial marriage too, make sure you have an emergency album of marriage pics, especially pheras, mangalsutra, etc. which you carry on day of US Visa interview. My vidhi was on 18th and we had asked the photographer to give us a temporary album of 100 pics showing vidhi and reception, so that we could show we got married by hindu ritual as well. It looks more authentic to the visa officer, and makes it appear more genuine. Its not essential, but useful if you can plan that way. Also, in case of H4 visas, while it should be smooth, leave time to reschedule and re-interview before Feb 1st so that, if God forbid your visa gets declined first time, you have time to do one more interview before he flies back.
Wish you all the best, and congratulations on your new life!!