US Immigration from Belarus

My fianc e is Belarusian and she is interested in changing her last name after marriage. Does she need to change her name in the passport to travel back home? Is this being done here in the embassy within the U. S.? How long is this process?

Hi reading from the pinned topic above regarding the documents to show common residency for the interview. Do I really need to add her name to every utility and bank accounts? I'm confused about what is considered acceptable.

K1 visa is part of NIE in some countries (https://travel.state.gov/content/travel/en/News/visas-news/updates-to-national-interest-exceptions-for-regional-covid-proclamations.html) - does it mean that beneficiary has to enter into US within 30 days period after visa issued?

From USEM in Poland site "If approved, the NIE will allow you only one entry to the United States within 30 days of the date of approval by the Embassy."

Does this rule applicable to K1/2 ?

So reviewing the I-129F instructions, I see at the beginning of the "What Evidence Must You Submit?" section that, after submitting primary evidence (or a statement if unavailable), you must "then submit secondary evidence such as church or school records, baptismal certificates, US census records, or other evidence to support your claim". Is this referring to what you must do if you do not have primary evidence, or is this applicable to all petitions? I presume this could just mean various documents/photographs that establish the relationship as legitimate, but I'm just confused as to why school records or baptismal certificates would be mentioned as they don't have a clear relationship to the rest of the petition.

Thank you in advance!