Can my son send his I-90 two weeks earlier before his arrival in USA in order to be sure to get biometrics in his 30 days stay?

Best thing to do is E-file it and then take receipt in to local office and get pasport stamped and request the biometrics

India to US on F1 visa,detained by USCIS. Can you please let me know what should I do to get more info on whats going on?

Try using this website, you may be able o find him/ her https://locator.ice.gov/odls/homePage.do

H1b extension while my case is in audit?How soon can I file for extension?Can premium processing done? Diploma Education?

You can file no earlier than 6 months before your I-94 runs out Even if you are in audit with your GC you can file premium processing if you...

What is best thing can i do ?

yes, that would one one idea, also try to email them . congressional inquiry could help too

Should I file for motion or file a new i-485?

A new 485 is sure to be accepted, but the fee is higher. have a lawyer review your denial and advise you . trying to do this on your own just cost...

Do applying for re-entry permit each time is OK? Are there any issues or law implication associated with re-entry permit?

i do not see an issue with this? Did you file I-485 with your I-140?

1. Can I legally stay in US for few months as a dependent of my wife, or apply for work permit given the baby situation?

You should look in to changing your status to J-2

How long does it take to be granted an asylum interview, also since i now have an EAD am i eligible for FAFSA?

here is the answer to your wait times https://www.uscis.gov/humanitarian/refugees-asylum/asylum/affirmative-asylum-scheduling-bulletin

There is always a risk of denial, however, it will NOT be denied merely for "upgrading": to premium processing

Evidence of selective service registration

You did not have to register in my opinion NON-CITIZENS Some non-citizens are required to register. Others are not. Non-citizens who are not...