You will need an attorney to pursue this matter with CIS.

No way - you don't possess any such power and/or authority. Only an immigration judge does.

Can I go for H1b stamping now?

The situation/dilemma you are currently in cannot be meaningfully analyzed on a general blog such as Avvo.

Country of residence in form i130A for green card application?

Cannot petition when listing an overseas address for the US citizen. That petition will be rejected if you do.

I want to withdraw petition for my step daughter? I'm about to divorce her father

Yes, you can still withdraw. Contact the US consulate's IV Dept. via email and also phone if you can.

Adding my 19 years old brother to one of my parents I-130?

Can do so if you wish, however, as explained, will be futile at this point,

How can I help ?

By hiring him both a criminal defense and immigration lawyer.

Why did US embassy stop responding to emails?

You need to pose that question to the consular staff, via email or if still a few unresponded to, appear in person.

Cannot changer employer and still hope to get "green card" when on EB-1(c).

How long will the joint sponsor form i -864 be reviewed during administrative processing ?

Most likely a few week or even months. Remain patient.