The Korean word for men in the sentence is for an individual man, not men. Should be 남자들
But in Korean putting 들 usually doesn't make much difference in a sentence, and since the topic particle is used (는), it's about men in general (unless context proves otherwise). So it is correct without the 들.
Men in this case can also mean man, in general. Man is fast.
It should be 남자들은 but you only use it to make an strong point. Korean dont really use plural very much
I think in this context it is man/men in general. It could be translated to Man is fast.
The 들 is optional depending on the context. In this case there is no context so both are correct.
Yes that is plural in English.
It strongly depends on the context. Could mean both.
So are woman
No, Jungkook is a bunny