The Koran is in Arabic and so are the required prayers. They aren’t done in native languages. For a long time it was forbidden if I remember correctly to print the Koran in any language except Arabic because of the required belief that the text is the literal word of God and if you translate it you are distorting it and committing blasphemy. Most have softened that and allow for translation, but it is still considered a pale shadow and the only authority is the Arabic version.
Correct.
Muslims recite all prayers in Arabic.
Remember seeing all those young men learning and memorizing suras.