Thanks! Glad you enjoyed puzzle 6 and the double zodiac, those were some of my favorites. Puzzle 11 was absolutely meant as a two-way street, I'm actually surprised that many people didn't use it as a key to the remaining puzzles. I guess it's because of the "puzzles should be attempted in the order given" thing.
In puzzle #8, the f9 glyph is an evil milk carton, to help players confirm that "foe carton" is correct.