Sunnyland

After you immigrate you will get your Green Card and Social Security Card.  that can take a few weeks. You should also get a state ID or Driver's license.  With that you will be able to work.
 
For your own business that is a state or local issue.  You go and get your license(s) and file for tax id numbers.

At your interview, the officer may ask for a letter or other document from your fiance's insurance company stating that you are eligible for coverage under his plan, date of estimated coverage (before marriage, after marriage?), pre-existing conditions coverage, if dialysis is covered under his plan, annual deductible, annual maximum amount covered, if medications are also required and the cost of those, regular doctor visits, and so forth.  Insurance does not cover 100% of the cost, your husband will have to pay some of it in addition to higher insurance premiums after marriage and family are added to his plan.  Given your condition, to avoid the public charge concern, I would suggest that your fiance should be asking these questions and that he should do the research with his insurance company and get the documents to show how much your treatment will cost every year, even with insurance it will cost something and depending on his insurance it could be a lot of money.  This is very different from the rest of the world and is often a shock to immigrants.  The officer might compare these additional costs to your fiance's annual income from the I-134 to make a determination about public charge.  Good luck!

Part of the adjudication for the N400 is to look back and make sure the initial GC was properly approved beforehand.  If it was moved to the fraud department, It sounds like something came up during the N400 adjudication that may not have been caught beforehand/raised suspicion as to the approval of the initial visa/AOS.  
 
Ask your friend what the IO seemed to focus on during the interview when it came to questions asked about her previous marriage.
 
As for responding to the RFE---your friend may have more evidence than she realizes....tax returns for those years during her marriage, bank accounts can be requested for closed/dormant joint accounts going back even 10 years depending on how individual banks keep records, shared utility bills for previous addresses/accounts as well (there is normally a nominal fee for these though).
 
Best case scenario is that her N400 is denied due to insufficient response to the RFE, and she can continue to live in the US and just renew her GC.
Worst case scenario is that USCIS moves to revoke her LPR status after any finding of immigration fraud on her part. 
 
 
 
 

Your friend should set up a VJ account and come here to ask these questions.  Only she knows what was said in the interview, only she will get the RFE.  It would be much more helpful for her to ask questions herself, so I suggest you encourage her to do this, no cost, easy to do, better results and advice for her.

Why would she even leave US in the middle of the process? The instructions are so clear, stating that it will mean abandoning the whole thing...

I see a few issues here
1st   it is Ghana and there are many denied visas
2nd   you are introduced thru a person/ he then would have been  a friend and you don't know how he died??????
3rd    you have not been together since the marriage 
4th    the CO saw the income was not sufficient  to  enable the visa
5th   you said wife had a  surgery  and you did not state the nature of her illness  and  that was  the questions
 
you overcome this by getting to know your wife better and prove  a REAL relationship 
she has to improve her income level
show she is not still ill and is able to provide so you will not become a public charge
prove you are educated so you can work in the US as married over 2 years the 10 year green card will be issued
and she reapplys  showing all of the above

Pretty sure this is the license, not the certificate. 

I guess that gives you an out, every three months.   Just kidding.   I hope it was the license.

Where did you get married? Never heard of a marriage certificate expiring. 

My story on AP. I traveled on my AP (while on AOS from K1) and on my return to POE Miami they sent me to secondary inspection. I was aware of this would happen because the custom officer told me that since I was traveling with the AP  he needed to send me to secondary inspection. He was nice.
Then the lady in the room had an attitude (she was very young and I guess new at this job) and kept questioning why I left the country, etc. I only spent 2 months in my home country visiting my mom who needed my help at that time. She kept me for like 1 hour or so staring at me weirdly like deciding if she would let me in or not. She let me wait until the last person left.
I said to her, what is the purpose of having the AP if can not be used for a family situation. Kinda that I got a little upset about the whole waiting. My husband was waiting outside for me wondering why it was taking so long.  She asked me if I had planned another trip which I replied not that I'm aware now. I will if I have to. She kept thinking.
At the end I told the lady that if she has any more questions, she could also talk to my husband who was worried already waiting outside. She just let me in. Of course after that episode, my next trip was with my 2 year GC and I had no problem at all at POE. 
Now with my recent acquired citizenship and US passport I will be able to travel "freely" with no concerns if they will let me in or out. 

Well Hell Yea!! That makes me happy! I freaking hated doing my wife's adjustment of status. Thanks for the info!
 
 

What are you smoking?

I said yes because they been known each other for about nine years and is only two years and four months she did not pay him a visit , may be due to financial reasons or whatever , But they are still talking as couples  and do get a lot of things going on between them .
He did not said they are separated or having problems between them .

Like most of them.... sides, immigration policy changes were known to be coming so, why are people surprised still?

If you feel better informing uscis then do it. The A# is an alien registration number and yes, is sensitive information and you don't want that to be flying around. It will stay with you until you become citizen. As per the pick up you should check with usps for that option. 

OP,  all what an attorney will do (if you consult with one) is telling you how bad your situation is and that the only way to be approved is if you hire him/her.  Unless the attorney becomes your co-sponsor then I don't see how they can help you in this matter. You will be wasting the money that you don't have. 

i wish i thought it was trolls. then i could just ignore it.
 
nope. im pretty sure its stupid people.
 
really needs to be an IQ test before you can petition someone.... just sayin .... lol

LOL.  But......wow!  I am always shocked and dismayed at the abject lack of research done by visa applicants.

Petition*
If your visa was in transit, you would have already interviewed, been approved, and the visa been issued.

you wanna hear a good one?
 
in a facebook k1 group im in, some couple had gotten an RFE. it was for an unchecked box, proof of meeting, and a court record for petitioner. pretty simple stuff to take care of. it had been 45 days or so since they sent their reply in and she was wanting to know how long it might take.
 
But....
 
in their reply, for proof of meeting, they said they GOT MARRIED in a non legal non binding ceremony.
 
her question was not about that (but it got my attention REAL quick!) but i told her she probably killed an otherwise easy approval 😕
 
all because they gave way MORE info than what was asked for.
 
i did actually feel quite bad for her. i know, rare for me, but it happens on occasion lol

Inexplicably, they seem to be on the increase!?

All those "Can I have ceremony before K1 visa/before POE" threads should just be locked automatically. It's getting ridiculous.
 
 

My story on AP. I traveled on my AP (while on AOS from K1) and on my return to POE Miami they sent me to secondary inspection. I was aware of this would happen because the custom officer told me that since I was traveling with the AP  he needed to send me to secondary inspection. He was nice.
Then the lady in the room had an attitude (she was very young and I guess new at this job) and kept questioning why I left the country, etc. I only spent 2 months in my home country visiting my mom who needed my help at that time. She kept me for like 1 hour or so staring at me weirdly like deciding if she would let me in or not. She let me wait until the last person left.
I said to her, what is the purpose of having the AP if can not be used for a family situation. Kinda that I got a little upset about the whole waiting. My husband was waiting outside for me wondering why it was taking so long.  She asked me if I had planned another trip which I replied not that I'm aware now. I will if I have to. She kept thinking.
At the end I told the lady that if she has any more questions, she could also talk to my husband who was worried already waiting outside. She just let me in. Of course after that episode, my next trip was with my 2 year GC and I had no problem at all at POE. 
Now with my recent acquired citizenship and US passport I will be able to travel "freely" with no concerns if they will let me in or out. 

Contact the embassy of Belgium in DC. They may be able to answer some questions you have.
 
http://unitedstates.diplomatie.belgium.be/en/embassy-and-consulates/embassy/address-and-opening-hours