With my idea, Americans are very frank and straightforward in social activities. If they like this person, they will show great hospitality to them.If not, maybe they are very indifferent.
about our punctuality, It all depends, it is very unpolite if you are late in commerce or date. But I gusee if it is a gathering of government officals in a city, mayor must be the latest to arrive.
The impression you gave us is very friendly, I have many Amercian teachers, teaching us English.they are very nice and hospitality. all of them are christians,
every week they will invite us to their home and tell us some stories about Bible.
Maybe Christians are very kind and nice.