What should I do?

Please meet with an immigration attorney to discuss your options. If a divorce is imminent, you may be able to request a good faith marriage...

My fiancee kids

It may be too late for the children to get the K-2 visas if she's already had her interview and is in the U.S. She may have to start her own green...

What are chances of my immigration case?

Discuss with an immigration attorney.

Can my husband apply I-485 while his I-94 already expired. His I-130 is already approved that is filed by me.

You need to be a U.S. Citizen in order for him to file the I-485 if his I-94 has expired.

Which category do I belong to on I-765?

Yes, it's (c)(9).

If H1b extension filed after my H1bVisa and my I94 expiry date, Can I stay in U.S?With in howmany day should I leave the country

I agree with my colleague.

Typically, a birth certificate is required. The Department of State reciprocity table may mention exceptions. Google that to see what is accepted...

Hello, will I be asked about I751 during naturalization interview - I 've been legal perm resident since 1993.

It would be good to work with an attorney on this.

Could parents that are permanent residents apply green card for married children , after citizenship waiting period shorter

See previous answer.

Could parents that are permanent residents apply green card for married children , after citizenship waiting period shorter

A parent can only file for you after becoming a U.S. Citizen.