Hun and sweetie said by a stranger just sounds less educated and outdated, and reminds of the days when women were not treated equally—think Mad Men. Having said that, some areas of the country just use it, and nothing bad is meant by it.
God bless you can be offensive to those who do not believe in God. Those of us who were raised atheists with the absence of this God talk feel very uncomfortable when people reference God. Expression like God Bless you, and I think even worse, I will pray for you, I could go on and on seem very strange to people not accustomed to church talk. Also, some atheists find the whole God/religious thing ridiculous so they just think people sound like idiots.
Little story: My sister-in-law said to me years ago, “I think it is so nice that the American president says “God Bless the United States of America,” at the end of his speeches. I am not fond of it, but don’t hate it. She went on to say in Mexico it would not be ok, that they have stricter rules of separation of church and state, due to the history of the Catholic church having so much power in that country. I found that surprising and interesting, since in my mind I viewed America as the country that values the separation strongly.