Should I file my taxes as married or single if my husband is a foreign national awaiting immigration visa interview?

I am no tax expert but it certainly seems like you are married and not single.

What is the best thing to do in this case?

This question has already been answered on AVVO.

Passport validity restriction for EAD on L2 visa

CIS can reject the EAD if your passport is not valid for at least six months. In short you should get it renewed before you file for the new EAD....

Can I Travel by Flight or Train within USA while in Removal Proceedings?

You are already in deportation proceedings so there is no reason to detain you. Your expired card and the extension letter should be fine but all...

Yes they can; your father just received one.

A-number in I-140,I-485,

Then maybe you do not have an "A" number.

NVC Case on hold

You do not need to do anything with the NVC. Assuming you have always been in valid status in the US, you will simply apply for AOS next month. ...

What does it mean?

That means you have been approved and they will send you the green card. Or not. I hate to say this but the online system is not reliable so until...

Can green card holders not living in USA give birth in USA?

You are not required to disclose your marriage. However, since you are out of the US so much it is probable they will not admit you. Or if they...

Can anyone tell me a good lawyer to apply for U-Visa?

You need to make sure the police officer on your case will support your U application and if he/she will do that, then you need a Board Certified...