Unless your naturalization was fraudulent, you have nothing to fear......The outlier cases are being reported as frequent. It's the corrupt and dishonest news media.
As I recall, my wife's NC came back as 1st class mail....USPS.....not Priority mail...so no carrier insurance at all..In addition, $100 only covers about 1/5 of the cost of a new NC. I would go straight to DOS.
You should enter any information you know (such as parent's name)....and you can enter "unknown" for information you do not know. "N/A" would not be appropriate in this case.
I would just use a copy of the 2 year card. You can explain at the interview, if asked. Plenty of people (such as my wife) used a copy of their 2 year card for the N-400 since our I-751 was still pending. The 2 year card (residence since" date) will establish when the Green Card holder became a legal resident.
I think you will receive good news soon. Keep an eye on the USCIS status. Remember to collect evidence for your I-751 through the next 2 years. Collecting pieces of evidence of a bona fide marriage along the way will make the removal of conditions paperwork a lot easier. Good luck on the rest of your journey.
USCIS says about 8 months for Dallas. I think it said 9 months when my wife applied in late 2022. It actually took only 3 months to get notification of an interview. Total time (over the holidays) was 5.5 months from application to oath (and that included a combo interview).