I MARRIED MY WIFE ON A K1 VISA.AFTER ABOUT A MONTH OF MARRIAGE SHE HAS NOW GONE BACK TO HER HOME COUNTRY.WHAT IS MY BEST OPTION?

Correct - If you are the US citizen, you are not required to do anything. Just do not file the AOS case for her since she has left the US.

Green card expiration date travel limitation?

I recommend travelling with the original I-751 receipt notice, your expired green card and your valid passport. You should have no issues at all.

Yes - so long as you have a valid green card (permanent resident card) and passport you should have no issues travelling internationally.

Do i need to fulfill sevis reporting requirements on f1 visa if i have received EAD from adjustment of status application i485?

The EAD issued in conjunction with your AOS case does not have reporting requirements so you no longer need to do so. The OPT is no longer valid...

Yes - your answer should be sufficient, but you will need a joint sponsor for the case to ultimately be approved.

Humanitarian reinstatement

You should really consult with an immigration lawyer. If the petitioner died, the cases may continue if the USCIS grants the request for...

I came to USA on B2 and now married to US citizen..What is my eligibility category on i-765?

You should contact an attorney for assistance.

I have a little bit English so can I pass citizenship test ?

There is a required English test and many sample questions online at www.uscis.gov.