Some stations might not allow you to sleep at night.
But most will.
The rule is. Either be at a place where everyone can see you or be at a place where NO ONE can see you.
Yea surely. i have experienced it. just like you i had that question and i spent one night at a.bad. then i did it for many time. it's fun sometimes, you will find good people and stories. just make sure to take platform tickets after every hour.
Yes, if you can manage and protect your stuff while asleep. Also, depends on the station, if its a big one like ISBT, even women and childern can stay with company ofcourse but if its a small station with not much activity, its not safe for even a single person coz u never know man!!
Yea .. if your with some male or group of friends it's safe .. but make sure you someone is awake when others are sleeping from your group ! because all times are not good ..