The use of the word anata

I study Japanese by myself and several times I came across observations on the use of あなた when addressing someone. All of them said to be careful because it could impolite given that it can also mean "darling". How true is that?

あなた can be used often from the third person to second person, such as teachers/tutors to pupils/students, a boss at work to workers. This mean does not always apply the higher position to the lower but I feel the person in lower position is difficult to say あなた to the higher position.

あなた can be used between husband and wife, but I don't think this is familiar these days.

あなた is also used more often by females, males will often use the more "rough" おまえ.

All of them said to be careful because it could impolite given that it can also mean "darling". How true is that?

That is very true. As suggested, it's not always used like that, but indeed you should "be careful" and it "can" mean "darling."

At the same time, a lot of people don't seem to recognise that, and even magazine articles use "anata" in strange usages, but in real life, I'd say your friends are correct.

あなた is also used more often by females, males will often use the more "rough" おまえ

That, I would say, is only true on fiction shows.

@Firas That's incorrect. In most circumstances, omae is very rude. You could really offend people by using omae indiscriminately.

@Juliabuqna Your understanding of the word is correct. Generally it is used only by people who are close, and it can mean darling. Personally, I would recommend that you just don't use Anata, omae or kimi until you have more of a feel for natural Japanese speech.

There are probably very few circumstances where you would need to use anata, as you can drop it if it's obvious from the context. When you feel that you need to use anata, use the person's name instead. It may feel strange, as we wouldn't refer to someone in the 3rd person like that in English, but it's normal in Japanese. When you don't know someone's name, I believe you can use Oniisan/Oneesan instead. I was called Oniisan by strangers a lot when I first moved to Japan, but I've been told by several people that it's a polite, but informal way to refer to someone who's name you don't know.

- The use of "anata" for calling out someone: it can be used by the wife to the husband, and it is used "Anata?" just by itself, simply calling out for his attention saying "Darling?"

- The use of "anata" in a sentence as a pronoun: not often done.
Instead of saying "anata wa dou omoimasu ka?" to ask someone "What do you think about it?" We would use the name of the person you are talking to, as in "XX-san wa dou omoimasu ka?"

あなた is also used more often by females, males will often use the more "rough" おまえ

that makes me think of this song:

http://www.youtube.com/watch?v=uY8Pn8jyJ-8