Without being able to review the actual certificate of disposition, I cannot comment whether there are any potential issues.

You should speak to the attorney handling the matter to determine what is actually needed. You will need to establish you maintained nonimmigrant...

The approved Form I-140 remains valid unless revoked. Whether you will be able to use it to obtain a work permit if immigration reform passes is...

Whether to expedite a case or not is with the sole discretion of the State Department. The State Department can deny a request.

You can certainly call the NVC but it is not likely to speed up the review process. Your case is progressing quickly. Hopefully, you filed...

You are not entitled to expediting. Expediting is a discretionary decision. The State Department can choose to expedite or not.

These individuals are other relatives. The form does not ask for only relatives that you are in touch with.

You should contact ICE. You can start with the field office where your son most likely entered.

You should notify USCIS and provide a copy of the divorce decree.

You should follow the instructions provided to you by USCIS.