In Denmark only close friends and family use words like "kære", "søde", "skat" and "ven". If you hear it from a stranger, they are either being condescending or sleazy.
If you go to the West country, you will also hear 'dove' and 'my lover'. In London, you hear 'darling', 'sweetheart' and 'lovely' more. My impression is that it is mainly used for people you know and not so much amongst strangers.
However, people seem to call each other 'mate' in all sorts of situations. The Danish equivalent would be 'kammerat' - you would usually hear it when someone is misbehaving and being told of though - but it is a bit old school.
