Mooochael- Thanks for the link! Berkeley wasn't, but now they are!
I noticed UCSD isn't on your list, have you considered it? They've got a great program and centers like the U.S.-Mex and CILAS. A lot of the professors are also adjunct with USD and SDSU. I'm more interested in the Politics/Economics side of things, but I hear they have a great program for those interested in the cultural/historical/sociological concentrations.
To answer your question about teaching in Chile: I taught at a public high school in Santiago while also attending the University of Chile, so I was only teaching one day a week (6 hours, 6 classes). It was a unique experience. The public educational system is severely underfunded so the classes were quite large and the disciplinary system in the school was basically non-existent. So, at times, I felt like a babysitter. HOWEVER, I did learn A LOT about the educational system and teaching English just through that experience and I don't regret it at all. If you have the opportunity to teach at a private school though, take it! If you're doing it through English Opens Doors, you won't make much money, but the cost of living is quite cheap compared to most cities in the U.S. and they provide free lodging and some meals with a Chilean family. I had friends who taught privately on the side and made great money- not sure if that's a concern for you, but thought I'd put it out there.
My recommendation: Unless you have another amazing opportunity in mind, I highly recommend teaching in Chile, or just doing anything in Chile. I can honestly say it was the greatest experience of my life so far. Chile is completely different from any country you'll know. The people are very welcoming, the travel opportunities within Chile and outside are amazing (Patagonia in particular) and don't get me started on the food. I have not doubt you'll be happy with your decision if you do choose to go.
I think that sums it up?
Good Luck!