Do not sign any affidavit. It is blackmail and signing it will only lead to more. Further, Massachusetts has no fault divorce. If he continues to threaten you tell him your attorney will be in touch and retain an attorney to respond. Blackmail is illegal.
DUIs are evidence of a crime of moral turpitude. You need to wait. Using the excuse tht you were driving alone and didnt hurt anybody does not make it right, legally or morally. The fact that there are two could lead an immigration to determine that you are habitual.
He needs to provide documentation of any criminal activity/charges/outcomes to USCIS; if will not be allowed to enter with certain charges on his records, but not knowing specifically what they are or when they occured I cannot advise you, and you should not provide specifics on this forum.
when you say cpermanent custody do you mean a permanent guardianship? Unless you want to adopt the grandson thbe permanent guardianship should be sufficient5. You can file a modificationand set a visitation schedule...some, none, or supervised. You should consult a family law attorney. This is a difficult matter even with an attorney. Good luck thank you for being caring grandparents.
I would not hesitate to go to the police regarding harassment charges. Your immigration status is no one's business. I would also recommend that you have an attorney (or maybe the police) call the person on the business card and let them know the situation. Good luck and sorry you are experiencing this.
A thorough review of your divorce agreement by a family law attorney for possible modification is your first step. You should do this quickly as the deadlines for selecting your son's school is probably May 1.
Your wife does need to be there unless you motion the court for her absence. Please be mindful that you need the divorce complaint, the agreement, the affidavit of irretrievable breakdown, and financial statments of each party.
You are not married, she cannot "discover" your assets. However, if she has filed a modification of alimony, then your boyfriend should seek an attorney to represent him as the laws have changed as to length of time, amounts, etc. with the Alimony Reform Act. Good luck.