In Denmark it is both acceptable and common. If a Dane asked another Dane the question you have just asked, the person being asked would look at the asker as if he/she had been from Mars.

I think it's okay. Get your bad decisions out of the way early :-)

Maybe you wanted to ask whether or not students should make friends with their teachers, Vivian? If so, it depends. If you are talking about school, my answer is NO. But if you mean high schools, I see no problem with this. 

I wouldn't recommend for two reasons the first one being some people when they get into a relationship with someone they forget about school, family, friends, work and everything else and that person becomes the sole thought on their mind, this doesn't happen to everyone but there are people who are like this I'm sure. The second reason I don't recommend dating while still in the academics is because what if you go through bad break up before your Uni days are done and you graduate? sometimes if someone goes through a really bad break up it can really destroy them and they stop focusing on their responsibilities like school. So I think it's best to get the Uni done and out of the way then find someone.