You need to speak to his attorney and find out when exactly his release date will come. If there are any other issues, his attorney certainly should bring them up on April 16 while before a judge that can make decisions.
Most likely yes you can eventually, however if he is not willing to sign the necessary documents then it is not a simple divorce. Fees are not discussed on this forum. Call a local attorney to discuss that aspect.
In New York, child support obligations last until the child turns 21, if not longer. If the father feels the mother violated his rights, then the father can petition for a visitation or custody violation order.
You need to speak with an attorney immediately in order to be prepared for your upcoming court appearance. If your prior history is clean, you may be able to avoid jail time. Feel free to call (718) 375-3750 to schedule a consultation.
Yes, you can receive child support and the judge/magistrate may compel him to pay your fees. It is not an easy process and so I do not recommend handling it without an attorney.
You would be well-served to discuss your dilemma with a New York domestic relations attorney in a confidential forum as soon as possible.