yes, it is considered impolite

you can use 'gorgeous'

chick is a slang for a girl or young woman who is attractive. but, i don't use it as i prefer beautiful, pretty or gergeous.

"Chick" is not an adjective. It means neither ugly nor beautiful. It is a slang, mostly used by younger men to refer to girls/women. Maybe you are thinking of the word "Chic"? Chic is a style. http://en.wikipedia.org/wiki/Chic_(style)