Princess Twilight Sparkle (or Cadance/Shining Armor, if they are available): I'm interested in the political status of the Crystal Empire. Is it a part of Equestria, a vassal state of Equestria, or an independent state? Also, are the Crystal Ponies OK with the fact that they are ruled by foreigners?
Rarity, what's the most expensive dress you ever made?
Applejack, what's your favorite food that doesn't contain apples?
Fluttershy, how do you earn your bits? (I have a few theories about it, so let's see which one gets confirmed, if any.)
G&P Trixie, do you have any memories to share from the period when you worked at the rock farm? Also, which member of the Pie family you liked the most?