Ed wrote:
The annulment is important to complete. Once a judge declares your marriage void, you should be free from any obligations or liabilities associaed with that man.
May or may not be true.
In terms of legal obligations ex-immigration it turns whether the marriage was void at inception or voidable. In the later obligations are valid until the time the marriage is voided by court action.
Petitions obligating you for support to USCIS are not impacted by whether the marriage was annulled or divorced.