Pacific Diana

Got an infopass appointment today. The guy who was helping me said that for  I751 applicants, many don't receive a biometrics letter at all as they tend to just use the previous ones. I asked if I could still do one as we will be travelling for a couple of months and that I didn't want to come back halfway should I get a biometrics appointment. He said I could try. They referred me to an officer and he created and printed out a biometrics appointment letter for me, and I did it 5 minutes later. Helps that it was surprisingly quiet today. I also managed to get a stamp for a year. He didn't take my NOA nor my Green card, just listened to my explanation (travelling + woman at SS office did not let me update my SS without stamp), completed a bunch of paper work, and handed me my passport back with the stamp.  Brought my passport, Green card, Drivers license, appointment letter, receipt, to the appointment.

To everyone having troubles looking up their case numbers on the uscis website, try using this site instead: https://myaccount.uscis.dhs.gov/. I was getting errors on the usual site ("At this time USCIS cannot provide you with information for your case"), but I signed up for an account on this new one and added my case, and it tells me "We received your biometrics fee and will begin processing your case". It also gives you your case history as well which is pretty nice. Hope this helps!

1) file jointly now. Start divorce once filed, then switch to a divorce waiver once you have final decree. This would be the easiest option. 
 
2) file for divorce now, file solo with a divorce waiver as late as possible before expiry of the card - if they were issue an RFE straight away this may work, as it has to be processed, issued, and you get approx three month response time.
 
3) file for divorce now, don’t sent I-751 with waiver and decree until finalized, regardless of whether this is after card expiry. 
For a divorce waiver you can file at any time - including after card expiry - between gaining permanent residence and a final order of removal by an immigration judge, and you remain in status and a LPR once you have. It clearly states this in the instructions. 
 
4) file jointly, inform them you are divorced but keep it as a joint filing even though divorced. Spouse would have to attend any interview with you though, so it relies on relations remaining civil (difficult!). 
 
 
Yes. Card remains valid by itself until end of the expiry date. 

The problem is, is you weren't living in his house. You had it set up so mail went there, but you only lived in his hours 93 days out of 2 years.

I had my DL and mail go to my mom's house for a few months after a moved, it didn't mean I lived there.

With that said, you need proof like joint bank accounts, joint credit cards, name on the mortgage or lease. You being the beneficiary of his life insurance, 401K and/or stock plans. Ya'll having loans together. Utility bills in your name for the home showing you pay bills for the home. Tax returns filed together as married for the last two years. Ya'll having pictures together. Things like that.

Saying "but we loved each other at the time, and I stay there when I visit" isn't even enough for a visitor visa from some countries.

I got a 2 year GC September 2016. 
December 2016 I left US. And been coming for couple weeks during this time.
Now I am preparing my trip to US.
 
Total - 94 days from date the GC issued.

you can apply with a divorce waiver....approval depends on proving you entered the marriage with bonafide intent, and other variables of course.