Can my husband get the B2 visa?

Once a person is getting stuck in AP, re-applying for new visas rarely helps. Especially, since I understand you filed I 130 for your husband, and...

What Documents do I need to prove that I never worked overseas during my long back to back trips?

I think you will need to prove that you maintained residency in the US...

How to apply for citizenship through parent?

You should start with visiting www.uscis.gov, form I 130 and instructions to it.

Can I change job while my 485 is pending?

It is possible, but you need to consult with an attorney not to make a mistake.

You can apply, but your application is unlikely to be granted. If you have a very serious issue, like medical a condition, etc. you can ask for an...

How can I go about applying for EU residency once I am already abroad?

You should probably start with consulting an Immigration lawyer in Spain.

How Can I emigrate to the United States

You need to have either a qualifying family member to sponsor or an employer. Also, you might look into investment options.

How much is the annual income required to.petition my siblings through my mom's application?

You may check I 864P guidelines on www.uscis.gov website.

Query related to US non immigrant H1B visa.

I might be confused, but you should have started your employment in the US long time ago. It is best if you speak with an attorney who was helping...

I-130 has been approved by USCIS. My wife abroad moved. Do I need to inform USCIS of the new address of my wife and how ?

Yes, of course. You will do it during communications with the NVC.