Legality of Stay in US with F1 applied and H1,i94 expired?

If you have applied for change of status (I-539) to F-1, you can remain in the U.S. during processing but you cannot work nor study until your...

Can I lose my spanish nationality?

Check the requirements for dual citizenship with your Spanish Consulate.

There is nothing you can do. When time comes for him to remove conditions on residence, and you have divorced, he will not be able to file jointly.

Changing my last name to my spouse's last name during the naturalization process?

You can change your legal name on form N-400, Part 2 n.4.

How should i proceed with applying for a marriage based green card under the circumstances?

If your marriage is real and you can document it, I do not see any issue. One thing is if she entered the U.S. on a B-1 visa with the intent to...

You can. However, be prepared to clearly explain the reason for your visit (if asked) and bring paperwork in support of it.

Can I get a 2nd RFE before my Employer reply to my first RFE ?

Unlikely. Talk to your employer and immigration attorney in charge of your case.

Can an F2 visa holder enter US that when F1 visa holder is in other country?

Sure you can. Make sure you have all papers for re-entry in the U.S. though.

Entered as a tourist did not get I 94. What to do for I 485?

Troubleshooting if you cannot find your I-94 online: - Did you enter your name the same way it appears on the passport? - Did you enter your...

Change of address after receiving interview notice for N400 application

Yes, you should show up for the interview in Houston if unable to reschedule otherwise your application for naturalization will be deemed abandoned.