1. You need to fill out the back of the summonses and attach Proof of delivery from USPS after you have these "green cards" (return receipts) or printouts from the USPS web page, which actually shows when the mail was delivered. I will file these in the court when I will have all my confirmations that the mails were delivered.
2. There is no rule when you should call the US Attorney's office. Some time will pass until they assign somebody to your case, and that person (the AUSA - assistant US Attorney) most likely will not begin working on your case immediately. People on this forum said that they called the US Attorney office in about a month after they served that office. I'll try to call them after Thanksgiving. You should tell them that you would like to introduce yourself to the AUSA who was assigned to your case (you should have your case number ready) and after they transfer your call to the right person, you tell him/her that you are calling to find out if anything you can help to resolve this case before actually goes in front of the Judge. Try to be very polite but firm, willing to cooperate with AUSA but don't get intimidated if they try that. Usually it pays out to build a good working relationship with AUSA. (S)he will work hard on your case to get solved before goes to the Judge, because they know that there is a high probablility that you will win. Nobody likes to defend a lost case...
3. For your case (and in all the similar cases) the ultimate answer will come from USCIS. in my opinion, it is highly unlikely that any Judge in this country would adjudicate your N-400 or I-485 application without a completed security background check.
The whole purpose of the lawsuit is to force USCIS+FBI to act. Usually, filing the complaint triggers an expedite request from USCIS to FBI. Most of the cases reach the completed name check and ready for adjudication stage before the lawsuit advances to the trial phase. But there were couple of cases where actually there was an order by the judge.
If your namecheck is not ready before the 60 days expire, the defendants (their counsel=AUSA) have to answer something, ask for an extension or file a motion. They do this 1. because are required by the court rules, 2. they want to buy more time to FBI+USCIS to complete your case. If they file a Motion to Dismiss, you have to oppose that, otherways the judge will throw out your case. Time is going, and most likely USCIS+FBI will be done with your case before actually an order is made by the judge. If not, your goal is that the judge order sends back (remands) your case to USCIS, BUT WITH A SPECIFIC TIMELINE! In other words, the whole purpose of the lawsuit is to force USCIS to finish you case in certain time.
I hope that this clarifies the whole process a little bit.