So far for people in our batch, the biggest source of stress comes from finding apartment while speaking little English. Each company is assigned a padrino, local Chilean entrepreneur to help out with picking you up at the airport and finding apartment. So, you will want to take advantage of that. I exchanged emails and setup Skype call with my padrino prior to arriving in Chile. It definitely helped with relationship building.
The other tip is to really use social media. There is a private Facebook group for Startup Chile participants. I found my current apartment through that. Also, if you are looking to talk to more participants before you get accepted into the program, try to join the meetup group at http://goo.gl/Hw67S.
Hope that helps,
Jerry