Yes, you can mail documents to consulates and embassies. You must verify addresses on website.

"Application" and "Decision" can be used interchangeably.

You may sponsor fiancée now LPR or when you become a USC. Consult and immigration attorney for detailed benefits and limitations of both options.

The I130 and I485 can be filed concurrently with no fees.

As of today, current processing times for VAWA cases, about 80%, is about 30.5 months.

To avoid to and from name change and concussion, you may consider keeping current name until AOS and naturalization stages.

Yes, the green card application process may begin without updating my wife's information and documents.

Upon receipt of your GC via H1B, you may safely withdraw your pending U application.

There is no immigration issue in your question.

It is possible to work for a US company, while on F1 from home in your counry.