I have a B2 visa, and would like to apply for a work permit, can I so that?

You cannot obtain a work permit incident to your B-2 status.

When can I apply for citizenship? I've been a US Resident since 2002 but moved to the US on Aug 8 2011 (Re-entry permits)

You refer to two different years in your question.

Can I travel to India 4 months before my H1B expires?

You can travel if you have a valid passport and visa.

Do I need to file an affidavit of support?

You can find detailed instructions for Forms I-864 and I-864A at www.uscis.gov.

DACA eligibility

Generally, there is no prohibition against filing for DACA and adjustment of status, but filing DACA when teh adjustment is pending may not be...

You should be OK as long as you can present the relevant documents explaining the name discrepancy on return.

Hi, My parents are on visitor visa.

You should file a request for extension of stay, otherwise they risk cancellation of their visas.

My Borther is Cuban living in Ecuador, Planning to cross US-Mexican border

If they are able to obtain parole into the United States, the wife may be able to later seek adjustment of status with your brother.

Security check remain pending for i485 under EB2.. Don't know how long it will take.

You may want to consider filing a mandamus Complaint against the USCIS in US District Court.

Can you please tell me by which month can we expect Supreme Courts decision on "Retention of Priority Date" under CSPA act?

The case was argued in December 2013. We are expecting a decision by June 2014.