Studied on F1 Visa and then changed status to H1B which I used for 3 years. Been out of the US for 2 yr, can I apply for B1/B2?

Depending on specifics of your situation a health break may be a basis for a higher than normal chance the B1/B2 Visitor Visa application will be...

One may obtain an H1B extension showing I 140 approval copy and H1-B extension receipt of prior filing and other documentation. CA AB-60 drivers...

Can someone who has an expired visiting visa apply for green card for a religious worker while in USA?

If the religious organization has an approved I-360 petition and the beneficiary has been expired less than 180 days. Otherwise the beneficiary...

How can I track down immigration/naturalization information?

You might explore USCIS Genealogy; https://www.uscis.gov/genealogy

What happens to OPT extension, as I switched company and got a RFE regarding e-verification on OPT extension and can I give info

the company needs to confer with immigration counsel to provide documentation.

I-130 approval? i-485 ?

An I-130 means the family based sponsorship is approved and is the basis for an I-485 to be adjudicated.

Can I give notice to my current employer

You may safely switch employers upon E-3 approval.

Can I apply for N-400 if I was absent 770 days during last 5 years? None of trips lasted more than 5 months.

Naturalization requires that you have been in the US at least 30 months of the last 60 months. Long trips within any one year less than 5 months...

Adjustment of status

US citizen spousal petitions with age differences of more than 10 years raise additional scrutiny to affirm the bonafides of the marriage. Parental...

Premium processing is going to get temporarily terminated from April to next 6 months. Will that affect the h4-H1B COS ?

All I-129 H1B Petitions may not request premium processing. The temporary suspension applies to all H-1B petitions filed on or after April 3, 2017.