OK. I went to use my girlfriend's computer and tried to remove the Better Terrain feature, but I could hardly get any work done as she was all over me and didn't leave me alone to do my Fairy Tale. Geez. Women.
At least, I know how to remove the Better Terrain. You need to work a bit with the Fairy Tale/Assets/Art/Terrain folder. Just remove everything except the Routes folder and the Resources folder in there.
In the Resources folder, remove everything but leave Crystal and Dragon Eggs in there, otherwise those won't show up in-game. Also, in the Routes folder, remove the River folder. This operation reverts the terrain foundations back to vanilla Civ.
Also, be sure to set the value for CustomArtFolder in the Fairy Tale .ini to one! This only has to be done if you have Blue Marble installed from before.