It will take a while to realize knowing English would not really help you much. IMO, it's important that you know some basic Spanish. But this isn't a deal breaker as I did not know any Spanish but eventually figured out enough words to get the job done.
Be ready to see people making out in the open, on the streets, in the metro stations and inside the metro standing beside you.
heh. the making out is partly because people here live at home for much longer, and, in the areas where i imagine startup chile people live and work (the idea that having to cook a couple of times a week is unusual made me smile...), there are also maids that live in people's houses (and so have nowhere private for guests).
also "making out" here would be petting, not sex...
food here is not spicy, but it is made with fresh, good quality ingredients (the sandwiches are awesome, imho). and the variety of food you can get in santiago is increasing (when i first arrived here, over a decade ago, there was just one indian restaurant - now my favourite place to eat is russian!)
Where is the Russian place? Being a Russian myself I would like to take a look at it.
Overall, I didn't have a culture shock after coming down to Santiago. The only thing that really surprised me is that many young people don't speak any English.. You can get by any where in Asia with English but it's different in South America.
Speaking spanish definitely helps. That said there are about 200 start-up chile people in the program at any given time. Everyone wants to make friends, so there never is an issue of who to hang out with.
Chileans also aren't used to meeting foreigners so in areas outside of Santiago - foreigners are kinda treated like celebrities.