I'd just like to say keep in mind that because one faction doesn't make something doesn't mean they can't use it.
They haven't really covered how ships will work in the game at all. If it's Civ5 style then EVERY faction may be able to move over ocean tiles early in the game via an "Embark" ability. They're just vulnerable to attack (by other factions or even sea monsters?)
If on the other hand transport ships have to be built like in earlier Civ games, MoM, etc. then even excluding using Dragon Turtles as ship replacements all a Draconian faction would have to do is capture a city of a race that does make ships and they can start building ships there.
Allowing every unit to fly while definately cool would be a very unbalancing capability. Especially with their natural armor and weapons as well. Finally I don't think having a move bonus in swamp and allowing them to move on coastal tiles without a ship is an insignificant movement perk.