I lived in Brazil for 6 months, 3 in Rio De Janiero, and 3 in Sao Paulo. Sao Paulo is a Mega- city, 29 million people and growing, not hard to get around in but fairly bland architechturaly, but active 24 hours a day. Rio has all the modern accoutrements, but actually is much slower, and is a beach culture. in most of the smaller towns I visited, there were areas like block parties where communities gathered, and interact. they don't have the at home electronics that we do, so they seem much more social. The weather throughout Brasil is very good to excellent, way south it snows a little, but most of the country has only 10-20 degrees difference. No major earthquakes, tornados, hurricanes or that kind of weather. it does rain and storm, often but of short duration. that can be dangerous in big cities, as it floods. There can be and is some anti- american sentiment, but just like anywhere, even here, stay out of the areas you don't belong. If someone tells you not to go somewhere, believe them.
I have spent some time in Ireland as well, and it is MUCH slower than America. away from the cities it is very quaint and nothing to do. If you are the reflective type, the solitude can be inspirational, but if you need stimulation, stick to the cities.
