I agree with my colleague, you should amend as soon as possible. Also, I would consult with an immigration attorney as to your overstay as it could...

As my colleague stated, misrepresentation is definitely ground for denial of your visa. The last thing you want to do to better your chances of...

In the military and marrying an illegal immigrant

Your question is a bit confusing. Is she here illegally or legally? What do you mean she pays money to be here legally? Either way, if you two get...

Will it be helpful If i become a US citizen to get my wife(indian citizen) a green card faster.

Probably. Depends when you filed for the F2A. Normally, if you are a US citizen, then your wife qualifies under the IR-1 category which makes...

Is it risky not to mention my previous marriage (Spain, divorced in 2009) when applying for green card after marrying a US cit?

I would not recommend any false statements on your application whatsoever. That being said, I think you should hire an immigration attorney to help...

My ex neighbour is asking me to be a witness when shes applying for a marriage liscence in NJ. Any legal issues involved

What sort of legal issues are you worried about? It's a bit hard to advise you, since your question is very vague.

My question involves civil litigation and the serving of subpoenas to non parties

I'd hire an attorney if I were you. What kind of subpoenas are they... duces tecum, ad testificandum? Were they served properly? Motion practice...

Will I have issues traveling abroad if my license and social security card do not match the last name on my passport?

I don't believe it should be a problem as long as you have other documentation proving who you are (possibly even a copy of your marriage...

Should file FORM i-864 with form I-485 ?

Absolutely! Also, there are a multitude of documents to send out with your I-485. As my colleague stated, if you are unsure or unaware of what to...

This sounds like a very serious issue and one you should address with a competent immigration attorney as soon as possible.