Just wanted to say love the whole idea of the year of traveling.
Oh and on a side note when you are next at SCL there is a business check in it is at the far left of the terminal same level as the rest of the check in desks if coming from the holiday inn and has its own dedicated passport control. Its not well sign posted at all, but I too had the same issue trying to find the business class check in.

Also the lounge issue to IPC can only really be solved if you if you happen to get the flight that continues onto Tahiti and a customs official who does not care as I had the fortune (as I don't think it is technically allowed) of using the premium check in and then going through the passport control, and in this way the boarding Gate used for the flight to Easter Island/Tahiti contains two sides one on the domestic and one on the international side of the glass wall but they lead to the same air bridge, so was able to use the lounge and get on the same aircraft.