Can I include my son on my i-485 or do I have to fill his own i-130 and i-485 and pay separate fee for him?

Is your wife a US citizen? If yes, she would need to file a separate I-130 and your son would go through consular processing abroad.

Is it common for an approved H1B to be revoked by USCIS after quitting working with the employer?

Your employer might have sent a letter to revoke it. They are required to inform when the employee leaves the job.

Can I go for H1b transfer while my extension underway?

You employer's attorney will be in a better position to cater to your concerns.

Got my initial OPT. I still have only one year visa remaining according to the visa stamping. Will I get my OPT Extension?

Expiration of your visa would have no effect on the STEM extension, if you otherwise establish the eligibility for the same.

The LCA is not specific to an employee, they would need to file the petition to have you work for them.

My grand-mother lived in the US for about 20 years, my mom for 4. I was born in Canada. Can i get a US citizenship

When were you born? There are more details needed doe a proper answer.

Depends on my Children.

Children can only file a petition for their parents once they turn 21.

How can I withdraw my affidavit of statement for sponsoring my spouse's green card.

What stage of the process are you in? Does he already have his green card? It will be better to explain everything to an immigration attorney to...

Can I still apply for the N600 form is there a time limit to do so?

N 600 can be filed anytime. If you are already a citizen, you can also think about applying for US passport, follow the instructions to see what...

What is meant by "Request for Initial Evidence Was Mailed" from USCIS for I-140 application?Is it like RFE?

It is RFE, You need to wait for it to arrive to see what exactly are you being asked for.