actually I realised I was wrong. I heard "you alright"

"are you alright?" is not a common greeting in my part of the UK (or that I've ever heard). It's simply "alright?". If someone did actually say to me "are you alright" I would take it as a literal question.

Within the US, "What's up" is a greeting in some areas and a question in others. In California it would be answered by another greeting, "Yo," "hey," "what's up," etc. In other areas (I know the southeast, not sure about others) the person would answer the question by saying something like "Nothing much," "I'm fine, what's up with you?" or something like that.

#11. It's the same over here lockedintheattic and the answer to "Alright?" is another "alright". I would ask "Are you alright?" if someone was hurt or something. Same as "Is everything alright?".

In Greek Τι κάνεις/κάνετε;+ literally means "What are you doing?", but in fact the meaning of the phrase is "How are you?" and the standard answer is +Καλά "Fine".
In Serbian one of the most common greetings is Đe si?, literally meaning "Where are you?", but in fact it means simply "Hey!"

To #13: The meaning is variable in the Midwest. I always hated being asked "What's up?" in middle school because if I responded with another "What's up" my interlocutor would say "I asked you first" and if I responded "Nothing much." he would say "It's not a question stupid, you're supposed to say what's up back".
Chinese only ask "have you eaten" around meal times. Usually lunch. They do want a proper answer. If you say you have eaten there will probably be no further questions. If you haven't they will express surprise that at whatever time it is you have not yet eaten, possibly concern.
Here in Beijing it's now arm-grabbing weather. All my neighbours will soon start grabbing me by the arm and telling me I'm not wearing enough clothes. That'll last about six months, then they'll start grabbing me by the arm and telling me I'm wearing too many. That's not really to be taken literally, again it's a concern thing. Also there is absolutely no point in arguing with their ability to judge how many clothes are appropriate for a given temperature.