MoonKnight,
Against. Fliers should always pay 2 moves per square. This not only balances them easier but also simplifies them in that they now fly direct paths rather than searching out roads like they do now.
At the same time they need compensation for the fact they can never achieve a movement rate of 1. I'd suggest starting with +2 moves for all fliers to get:
Crow - 11 squares
Eagle - 10 squares
Ghost - 11 squares
Gryphon - 8.5 squares
Pegasi - 10 squares
Archon - 8.5 squares
Demon - 9 squares
G Dragon - 13 squares
G Archon - 9.5 squares
R Dragon - 12 squares
I an open to the idea of them being transported by boat in the same matter land units are if their movement was converted to boat movement (ie lowered to the ship movement number). As I mentioned above, this is the one place where it makes sense for them to get a different movement rate. But I realize that's a lot of extra coding.
KGB