If the document is in your country's language then no need to translate but if this is an out of country document that is in their language then yes it needs to be translated. If it's in English no need to translate.
First is If you have an experience with a contract of employment from your native country after entering the US with K1 visas. My employer in my home country will allow me to work externally for them. I'm mainly asking because of social and health insurance. Is it therefore possible to work still for a company from your native country and have a classic employment contract with them?
Where should I report this (what kind of office) in the US to prevent that both countries (US and native country) won´t pay social insurance at the same time?
How is it with the health and social insurance before marriage?📰
I am asking mainly because of the time before the wedding after entering US (we won´t get married the next day after my arrival :)) and before the necessary documents and work permit are handled in the US.
Or should I solve this with employment Department in my native country?
^ This.
For example, missing letters of intent to marry might take a few days. Missing divorce or court documents might take longer since they need to be validated.
What was the reason for an RFE? "Simple" ones (i.e. a missing document or such) usually don't take that long - days to weeks. More complex ones could take weeks to months.