Just Paul

You don't need to owe tax in order to file a tax return.

Slow down and read the answers.
 
She has an attorney or she can contact the USCIS ombudsman, she can contact the State Department.
   
Her not taking an active role does lead me to believe that she could have withdrawn the petition.

The question is establishing your ability to file a petition.    Are you a US Citizen - Yes.  If you have an A number put it in if you know it.

Nothing for you to do.  The petitioner needs to be involved.

That is a rare reason that a visa would be refused.  Usually at the interview the consulate will tell you to get another sponsor.
 
Being refused (or revoked) during AP stage indicates that something came up on the background check or there might have been something the consulate saw on the petition.   The petitioner or the attorney should attempt to verify.   You, yourself will have a hard time finding out.
 
Do not spend more money until it becomes clear what the issue is.

Nothing for you to do.  The petitioner needs to be involved.

That is a rare reason that a visa would be refused.  Usually at the interview the consulate will tell you to get another sponsor.
 
Being refused (or revoked) during AP stage indicates that something came up on the background check or there might have been something the consulate saw on the petition.   The petitioner or the attorney should attempt to verify.   You, yourself will have a hard time finding out.
 
Do not spend more money until it becomes clear what the issue is.

That is a rare reason that a visa would be refused.  Usually at the interview the consulate will tell you to get another sponsor.
 
Being refused (or revoked) during AP stage indicates that something came up on the background check or there might have been something the consulate saw on the petition.   The petitioner or the attorney should attempt to verify.   You, yourself will have a hard time finding out.
 
Do not spend more money until it becomes clear what the issue is.

Traveling on a tourist visa means having (and being able to show) strong ties to home.  This applies to everyone on a non immigrant visa.
Having a tourist visa before filing does not mean it is cancelled or impaired by filling.  But trying to get a tourist visa after filing does create issues as the petition signifies immigrant intent.
 
People come here all the time with petitions pending.  People come here for destination weddings.
 
Having lack of confidence entering the US at the POE can cause issues.  So always enter like you know what you are doing.
 
There are thread all over here about being able to visit.   There is even on pinned at the top of the K1 and spousal pages.
 
 

Sounds good.   Remember to save a copy of everything.  Apparently the two of you missed that key concept and it is costing you another delay of 3 to 6 months, probably more.

It does not matter if you are married one day or one year as long as you can demonstrate that your marriage in bonafide in the petition.   It will take USCIS 7 to 12+ months before they even review the petition and you can gather more bonafides in that time.

What step of the process are you at?  Please update your timeline.
 
If she is truly exempt from filing then she just needs to explain why on the petition or in an  attachment.
 
Why do you, the beneficiary, have a lawyer?  Where is this lawyer? Something isn't right.

What step of the process are you at?  Please update your timeline.
 
If she is truly exempt from filing then she just needs to explain why on the petition or in an  attachment.
 
Why do you, the beneficiary, have a lawyer?  Where is this lawyer? Something isn't right.

What step of the process are you at?  Please update your timeline.
 
If she is truly exempt from filing then she just needs to explain why on the petition or in an  attachment.
 
Why do you, the beneficiary, have a lawyer?  Where is this lawyer? Something isn't right.

I'm sorry we didn't give you the answers you wanted to hear. 
 
What works best for you depends on a lot of factors, and people are asking you questions because you are not giving us much information that would help us to help you. If you don't want to answer those questions, use this website to do your own research. Read the guides, browse the forums including the regional forum. 
 
But first, get to know this person before planning a wedding and an immigration path.

Sounds good.   Remember to save a copy of everything.  Apparently the two of you missed that key concept and it is costing you another delay of 3 to 6 months, probably more.

Filing jointly should reduce your overall tax. In order to file jointly, your spouse needs a SSN.   The EAD status is not relevant to filing a tax return.  Without the EAD the spouse should not be working. 
 
Just file Married filing Separately if that is too complicated for you.

No idea.  That is up to you and your girlfriend.
 
You haven't provided any meaningful details of the relationship. 
 
It is pretty clear that you both haven't done the research to see what fits for you both.

Nothing is guaranteed.   Read the guides and the forms and see what fits better.

Like @designguy said the decision is mostly conceived based on what is in the application. Take whatever helps the case with you.   Helps to be over prepared.

No idea.  That is up to you and your girlfriend.
 
You haven't provided any meaningful details of the relationship. 
 
It is pretty clear that you both haven't done the research to see what fits for you both.

Rightly so . . .
"If a country wants to fully participate in U.S. immigration programs, they should also comply with all security and counter-terrorism measures — because we do not want to import terrorism or any other national security threat into the United States," Gidley said in a statement.
 
https://www.rferl.org/a/us-planning-to-add-belarus-kyrgystan-to-travel-ban-list/30389956.html

On United . . . It was a pain.   Now they fly 737 between Guam, MNL and Tokyo.
 
PAL does fly LAX-MNL and the seat pitch is not for Kanos

On United . . . It was a pain.   Now they fly 737 between Guam, MNL and Tokyo.
 
PAL does fly LAX-MNL and the seat pitch is not for Kanos

You are fine to do Global Entry.  TSA-Pre only covers departures, not international arrivals.  Once you have the conditional approval you can do the interview.   If you are lucky enough to get it before you return to the US you can do the interview at the immigration area of the airport.