"Try not to tell people how to run their country, get workers to be more efficient, solve government problems, or criticize slowness in doing things." In Latin America things generally move slowly and you must be very patient. Sometimes at government offices you have to wait in line while the attendant is away brushing her teeth, polishing her fingernails or putting on make-up. If you complain, you're liable to get poorer service. There's a feeling among some workers that if they work too fast, the value of the work is lessened or depreciated, and not really appreciated by the one who is receiving or paying for it. I attribute the real reason to be a lack of motivation, which though to a lesser extent, also exists in private enterprise.
"Try not to gush or give out undue compliments." Those receiving them are not dumb. Sincerity that is false usually is not rewarded with friendship. Flattering that is too extended or visible doesn't produce good results.
"Be careful when you make in public to a parent or friend a bad comment in English about the country." You might feel you are not being heard but in Costa Rica many of the local population understand English and someone close by could hear you and feel bad about your criticism or wisecrack.
"Keep away of telling dirty jokes or conversations based on sex to try to break social ice "You will mostly be embarrassed or misunderstood. What appears to be a good joke or piece of conversation to you may be badly received by your listener. Jokes and puns in English usually do not translate well into Spanish and it's difficult to capture their real tone and meaning. Thus, if you're not sure how it might be received, don't tell it".
Good Manners Will Win You Points
Don't be boisterous or speak loudly nor blatant in manners or dress. Politeness and speaking softly go hand in hand especially among Costa Ricans. They appreciate this and consider it good manners. This is in contrast to the loud Spanish speaking Cubans, Puerto Ricans, Dominicans, Panamanians, and northern coast Colombians. This usually occurs with people living in coastal areas. Perhaps that's why Mardi Gras and such carnivals and rowdiness are much more common in coastal cities than in those inland. In highland Guatemala, the uplands of Mexico and mountain areas of other Latin-American countries, the people speak in even lower tones than they do in Costa Rica.