Is France the only "old" Civ that has been revamped or are there changes to other Civs as well? If so, would you mind sharing or hinting at any of these changes?
No civ has been as dramatically revamped as France. But you’ll see (subtler) changes to India and Arabia to name a few. Also we are finding that some civs (Polynesia, Rome, Carthage) have been indirectly strengthened by the new systems in Brave New World.
Are there any ideology specific wonders in the game?
Each Ideology has a Wonder associated with it. Once that Wonder is built, then no other Civ with that Ideology can build the Wonder!
Are there going to be any non-Indonesian new luxuries? Or any new bonus resources?
No. The Luxury Resources (outside of Indonesia’s unique luxuries) are the same as Gods & Kings.
Could you elaborate on Indonesia's ability?
The first three times Indonesia founds a city on a brand new continent(where it hasn’t yet founded a city) it gets two copies of a special resource: Nutmeg, Cloves, or Pepper. This resource cannot be razed or destroyed. Indonesia has the option to trade any of these resources it wishes.
What does the Caravansary do, and would I be correct in assuming that the East India Company is its associated National Wonder?
The Caravansary is a Classical-era building that improves the range and Gold yield of land trade routes heading OUT of a city. The East India Company is a National Wonder (replacing the earlier National Treasury) that is associated with having Markets in every City. It’s effect is pretty much the reverse of the Caravansary, providing a boost to routes that connect INTO a city.
