Best to have an attorney review your entire case history to best assist.

Depends on the admission process for the schools you are applying to.

Provide the last best approximation of your address outside of the US.

Provide the best approximation of the last address outside of the US.

Yes you should include all periods of employment for last 5 years.

It will take 30-90 days for review by NVC.

No this will likely not be requested by NVC.

No the original certificate should not be necessary.

You can provide the information at time of interview.

Depends on your particular circumstances. Best to consult with an attorney for guidance.