Can my wife (from Australia) start working without having received her employment authorization letter in the mail?

Unfortunately, your spouse will not be able to be lawfully employed until she is in possession of the EAD.

The revocation of the F-1 visa merely revoked that F-1 visa and not your F-1 status. If USCIS approved your change of status to the H-1B from the...

If I travel with an expired green card, can USCIS terminate/abandon pending N400 app?

The FORM N-400 will not be impacted by your departure from the U.S. for a week. However, CBP may cause you extended delays at the U.S. port of...

Immigrant visa while being outside

Your employer can file the FORM I-360 while you are abroad. You can view the processing time of the FORM I-360 by accessing the USCIS website.

Getting Married to a US Citizen while on H1B Visa, What are the possible options we have?

You can contact the Indian Embassy in Washington, D.C. to inquire about a name change and a new passport. If you file for adjustment of status...

Can i break a signed offer letter and accept other employment offer from a company on H1b

The job offer that you "signed" will dictate your obligations to the prospective employer. You should visit with an experienced immigration...

The spouse for whom the application is filed is the petitioner of the FORM I-751.

B2 while waiting for K1

If you are the beneficiary of the FORM I-129F petition, the U.S. consulate will not issue you the B-1/B-2 non-immigrant visa.

What advice should you give regarding this matter?

You can present the birth and death certificate of the deceased child to the U.S. consul at the time of the immigrant visa interview.

Unlawful present and applying new Visa

According to your fact pattern, the response is "yes" since you have been unlawfully present in the U.S.