I don't know if these people are just plainly not polite or it's simply not rude for Vietnamese people to:
1. Ask for your age.
2. Ask for you weight and/or call you fat. Sometimes you'd get a bonus with a description. example: Lola, your face is as round as a full moon!
3. Ask how much you make....yeah, seriously. Then that person will comment how rich or poor you are.

4. Ask how much your blouse, purse, shoes, whatever you have that that person is interested in knowing the price. Then he/she will say how rich you are if it's a costly piece of item. Well, costly or not is relative. And no, he/she isn't really interested in buying the inquired item. They just want to know how much you put out for your stuffs.
Is it okay for Americans to ask if a person is married or not or in a relationship or not? Just wondering because Vietnamese people will straight out ask this too.