Nga&John

Get a social security number then go to work for money, nope. Chance: slim to none.

Well... OP needs GC to move on with her life, who needs a husband anyways? Seriously...

EAD and AP will not be issued (no RFE of course) until several months after biometric. You can't leave without AP.
I693 is one of most mandatory forms, they might return whole package just for it. Do it now and include with the AOS package.

They don't just deny you that easy. If there is interview, you will have interview by yourself. Gather all bona fide evidences for your case now. There is at least one member here, she filed ROC with divorce waiver and she didn't have interview.
Remember stay married just to get ROC is fraud. There is no such "support" or "help" as you mentioned.

Keep in mind if FBI has problem with your fingerprints you might be called to take biometric again. It's rare but it happened.

You need to have at least a document which has a certain period of authorized stay to apply for DL.

Exit Visa you meant Re-Entry permit? Her continuous physical residence has broken, she will be able to file N400 4 years and 1 day minus her time of staying from her last trip (at least 6 months you stated)

I also think you can check if the money order was cashed. A personal check is fine, and gives you the chance to check, but too late now.
You can
1. Call USCIS and get a Tier 2 person to look up your case and give you your case number.
2. Make INFOPASS and get a I-551 stamp in your passport in lieu of receiving an extension letter.
Do both of those things. Good luck.

I believe you can call the money order issuer to check if it was cashed (moneygram, western union...)

Wait, you said UPS or USPS? Because I don't think UPS deliver to PO box. If it was USPS then was your check cashed?

Your colorful folders will annoy and confuse examiner, they are not children so you don't have to colorize/ highlight everything. Just stack everything up in order of your head-letter. You will be fine. Good luck.

I wouldn't use the folders. They are likely to throw that out anyway. I would just paperclip each section.

I do think your folder is very nice, but it's also known that the USCIS officers have a set organization method and agree that it would probably be better to leave the folders out.