1) What could be the ways he can delay the divorce process?
Opinion: Its depend on him, he may delay to accept the summon, he may manage the post man, he may delay to file the written statement, he may delay in evidence, cross examinations, etc.....
2) I can also file in Kolkata as we got married in the city but are settled in Delhi. Any idea how much time do the courts in Kolkata take? Are Delhi courts faster than Kolkata?
Opinion: Delhi court is more faster then Kolkata, so it will be better to file the case in Delhi.
3) While I have documented evidences to proceed with DV, alimony and maintenance; somehow I don't feel comfortable using those options and want to fight the case on merit. Will the court accept emails of him apologizing for subjecting me to mental abuses as evidence?
Opinion: the emails or other digital evidence is accepted as Evidence.
4) Can I go ahead and sell my stake in the property today. There is no loan or any other liabilities on the property but his parents and my brother in law and his wife are also living in this apartment. The parents own their own property in a different city. How do I go about doing a pre-empting offer? Is that a legal letter that my lawyer should send them? Just worried that they will not respond and then claim they didn't get it. Can I publish the letter in a newspaper?
Opinion: you may send a legal notice related to your property and claim the same or demand the money against your share. Newpaper publication will not be better option