I have a daughter in Mexico, though in Nuevo Leon State so far north of where you are going. That said I have been to most of Central and South America. The only nation I didn't care for was Brasil, and that was a language thing (Portugese gives me a headache).
Many tips I suppose but it depends on exactly the locale. My most memourable experience was in Guatemala. I was there when white skinned people were being beaten senseless and even killed. Most of the nation is Native American and a bunch of rumours had started about "baby snatching," for re-sale to Americans.
Actually began when 2 travelleing salesmen, locals, ran afoul of drunks at a Fiesta (each town, and in the cities each neighbourhood has a Patron Saint whose Saint Day is celebrated with a raucous Fiesta). The violence lasted a couple of weeks and I was travelling by bus as I so often do.
Peru was just coming out of Sendero Luminoso, who by the way are active again so watch yourself if you hit the Andes in Peru, as well as part of the Basin. Same for Colombia, FARClandia is not a place you want to go. ELN is calm nowadays but always watch your Ps and Qs.
My favourite part of Mexico, hands down is Oaxaca. Best food, prettiest people, best accent in Spanish. It is funny. I speak Spanish better than English since I am a Ladino speaker. Yet, when I went down there and spent only 10 days in that area, ever since I have leaned towards its accent and get pegged as a Mexican (Huero, meaning White Mexican though there are many Judios/Jews in DF and Monterey).
Also, to Oaxaca's credit I was there during the Zapatista brouhaha with Sub-Commadante Marcos and was safer probablly than any other part of my trip, including Argentina which people assume to be as safe as any American city.
If I could go again? I would go to Surinam and spend time with Bush Negroes, what a fascinating People! I also want to try and see how easy it is to learn Papimiento, the Dutch Creole Language.
I would spend time in Honduras' Bay Islands among the Garifuna People. I lived among them in the South Bronx and find them to be very interesting as well. Most people don't realise that the Caribbean coast in Central America is filled with English Language Peoples like them, the Miskito in Nicaragua, etc, etc.
Panama? You have that one correct. Not much to see until the Colombian Border area and of course FARC operates north of the border so stay away. Panama is one of those places like Abu Dhabi, the Dollar is king, anything you can afford can be had and an American puppet government make it unpalatable to me.
Chile? Now that is spectacular. The fjords are to die for. There are towns that could have been plucked out of the Bavarian Alps, people and all and German more popular than Spanish. I think I could spend a good year there and never be bored.
An area there I did NOT see but wish to is the pampas near the Argintinean Border. The Vaquero Culture is dying fast, but sheep ranches, pine forests, its something I would love to get a look at.
I did see some of the Argentinean pampas because of family that live in the Jewish town of Villamoises [sic]. Founded by the Rothschild Clan, as an alternative to Ottoman Palestine as a safety net in case the Zionist scheme for Palestine failed.
Mostly though my family is in the Palermo area of Buenos Aries. Gorgeous city, close your eyes sometimes and it seems as if you are in Paris, but with friendlier locals and better retail service hahaha.
I would like to really see Montevideo, in Uruguay having only spent 2 days there and I want to go to 2 locales in Paraguay, Asuncion and the 4 Corners region, the capital of Arab South America (borders of Paraguay, Argentina, Chile and Brasil).