Do I need to file a new I-130 for my child once he/she is born?

The child (who is minor) would be considered a derivative and can come with your wife to the US.

You can submit proof of US citizenship like your US passport if you don't have the certificate with you. It is better to enter " unknown" or not...

I never went to Jail or I never handcuffed by Police , Do I still need to say YES for have ever arrested question in DS160?

Yes, being arrested does not necessary means you were handcuffed; from what you say you were arrested.

I-539 denial

If you don't have a valid visa, you will not be admitted to the US. If your country allow entry without visa (ESTA) you could enter without visa.

Do I have a chance to file and approve cap exempt petition of H1B that was approved in 2008 and never used till date ?

An cap exempt H-1B can be filed for her.

Do I need a new F1 visa to enter the US if my SEVIS was terminated?

You would need to consult an immigration attorney.

How risky is it to work outside your field of study when on OPT?

I agree. If you work outside of your field this would be a violation of your F-1 status. As a result you would not even be eligible for H-1B since...

Usually notifying the US embassy, or showing proof of life in Canada for 11 years (paid taxes, bills, property etc..).

Does using the social security benefits for a senior green card holder have any effects on citizenship process?

It might not disqualify him for citizenship; however, things might change.

Previous J1 sponsor informed US Department of State of my “violation” of not going back home after traineeship. Help?

When you are on J-visa you need to return to your home country for 2 years after completion of the program unless exception; otherwise you might...