I601a approved, aside from DS-260 and additional paperwork. Do I need an i-212 prior to departing to consulate interview?

Generally no - contact a US immigration attorney to determine whether the I601A waived all issues before leaving the US.

Review the instructions at www.uscis.gov and contact a US immigration attorney. Based on your facts, generally no.

As LPR, based on your facts, you may change employment, preferable to something similar. Contact a US immigration attorney.

Can I work with my old social security number while waiting for it to be updated in Social Security Database? I am a LPR

Yes, you only receive one social security number per lifetime.

Stem opt card lost

Review the instructions at www.uscis.gov and contact your DSO.

I HAVE A LADY FRIEND THAT WANTS ME TO BE HER SPONSER FOR A GREENCARD BUT I WANT TO MARRY MY BOYFRIEND WHO IS FROM MEXICO. CAN ?

Yes if your income is sufficient. Review the instructions at www.uscis.gov and contact a US immigration attorney.

STEM OPT EXTENSION

Contact your DSO and/or US immigration attorney for eligibility review.

Can I apply for Stem opt extension after the one year deadline?

Previously asked and answered - review previous posting.

Will the change of an adress (to a different country) of my fiancee affect our K1 visa case?

It will take months to transfer the case. Contact a US immigration attorney for assistance or try to keep the case as scheduled.

Previously asked and answered - review previous posting.