Requesting copy of immigration documents from UCSIS?

Sure file A FOIA request. Your renewal of GC is separate adjudication

J1 hardship waiver and B/B2 overstay( US government funding) ?

Depending on your set of circumstances, a hardship waiver may be an option. Discuss in private, with counsel of your choosing.

Guidance requested: which legal expert(s) i need to consult for this unusual "mistaken" loss of Nationality issue?

Seek an advice from a licensed accountant as this relates to tax implications

Looking for advice in transferring from H1B(Work Visa) visa to F1(Student) Visa?

1. Can do Change of Status in the U.S 2. @ least 45 days prior to one’s current status expiry

Will I-130, Petition for Alien Relative still valid ?

He will drop down in preference category and his wait time will be longer. Consult in private for clear understanding with competent immigration...

Not normal practice to issue or have multiple work authorization permits

What is the soonest I can apply for citizenship?

2 years and 9 months if you were married to a US Citizen and alternatively 4 years and 9 months if you were married to a Green Card holder.

All time spent in home country, cumulatively, counts towards HRR. Just had a client with this pattern who adjusted status.

Has the birthright citizenship changed recently ?

For DS-160 consular interviews there is questioning whether foreign national is pregnant and CBP has authority to deny admission to an expecting...

Denial of citizenship after 3 years wait?

It is not possible to advise without reviewing your N400 denial. Consult with an attorney.