That's a good point, Waterwings. Being one of the most visited tourist destinations, I am sure local people of Aruba have entertained and dealt with people coming different countries with different cultural backgrounds. It makes them more tolerant. If we happen to do something offensive to them, they may think that it's just our of our limited knowledge about their culture.
I created this question because of the old old TV commercial of FedEx. A man gave a thumbs up to a local bar in a country where he is visiting and all the people inside the bar gave a bad look at that man.
I think the locals in Aruba are the ones who are careful not to offend the tourists. I agree that they should be tolerable with the actions of the tourists.
Just don't be rude with everyone and don't take things too seriously. This is my motto when I go to different places where I don't know the culture. There are universal actions like smiling or frowning that everyone can understand.
I agree, facial expressions will tell a tale for themselves. If you really want to be safe, just don't use hand gestures, like "flipping the bird" or "thumbs up." Most of the locals are pretty laid back, so just don't act like a jerk and you should be fine.