Oh man, that's way more complicated than anything I've DIY'd so far...
Why do you think that I-290B is not the way to go? I've had lawyers recommend that route.
Getting a receipt number for I-485 seems to take over a month in a lot of cases, so I wouldn't be able to provide a receipt notice with my response to NOIR, only a copy of the filing itself... And then it will be handled by a different service center (NOIR comes from FO, I-485 handled by NBC).
Is there any reason for me to escalate the case to court? (and how do I do that?) Or will USCIS do so if they are not satisfied with my response?