Thank you, and I’m always happy to hear that people find this useful. Buenos Aires is a wonderful city and it feels very modern and very European, at least compared with most of the rest of South America. I would think that bringing a baby there would be similar to bringing one to, say, London or Paris. Rio de Janeiro is perhaps the most beautiful city location on earth, and it’s got some very rich areas (mostly along the beaches) and many dodgy areas. They also seem to struggle more with infrastructure there so bus service isn’t very modern and that sort of thing. That said, I haven’t been since they hosted the World Cup and Olympics and I’ve read that much of the situation has improved. Long story short, I think you might just have to be a bit more careful in Rio when choosing a hotel and neighborhood and that sort of thing, but generally I think you’d be good.
Southeast Asia is easier to deal with, and there are cheap flights connecting in the Middle East and landing in Bangkok, Kuala Lumpur, and Singapore. Each of those is a very interesting city, and there are many smaller places to go in the same region. In Malaysia there is Penang and Melaka. In Thailand there is Chiang Mai and quite a few others in that area. In Laos you can visit Luang Prabang, which sounds like it could be a winner for you. And there is also Siem Reap, which is home to the amazing Angkor Wat temple complex.