Thanks for the answers, DivineGamer!!

Actually, I just found out on a fansite that indeed, the dragon form can not walk on terrain but only fly (bit of a shame, but I suppose they wanted to keep the "human battles -> ground" well separated from "dragon battles -> sky"). I think maybe this question could be eventually added to the official website's FAQs?
Oh, and I'll be waiting and hoping that others of my questions can be cleared! Specifically, the one about the visual difference of dragons according to their gender; and the one about the dual core vs single core.
4.Don't get what you mean.
I basically mean if it will have a good, branched, long plot or if it will be more centered on hack'n'slash and exploration mechanics.