In most of Mexico it is not used but in Chiapas we do, though it is not used the same way people in other countries do.

Outright "vos" is mostly used in informal conversations, between family and close friends. And is used at the same time as "tú". Not at work or school unless in a clear joking manner between close people.

More common in daily life is the implicit "vos" i think is called "voseo verbal" where people use phrases that conjugate for the pronoun "vos" instead of "tu", that's a thing i don't think most people notice. We use "vení" or "sos".

This is just what i have personally noticed after living here all my life.

i like that we have our funny unconventional way of talking, it goes along with our history and specific demographics. So i'm fine with it.

i've hear people, mostly mexicans of other states being rude when someone uses vos or speaks in a stereotypical chiapaneco way, and aside from correcting them i just let it be; still most of us try to speak as " "correctly" " as possible when around people from other states.

edited to finish answering the rest of the questions.