In no particular order:
Utilt's extra hitbox is hard to hit, while dair's is insanely easy. Part of this is the size of the hitboxes, but an equally big part is that it's easier to line up dair. Many characters can dash -> crouch -> utilt in under a second, but Zelda has to spend extra time dashing before she can cancel into crouch. So if your opponent is even a little off horizontally, there's no way to quickly move over and utilt.
Her ftilt fits her "glass cannon" style of play. If it hits, it puts your opponent right where you want them, but if your opponent shields or dodges, you're going to be punished.
Neutral b is a nice mixup while recovering, but I'm pretty sure it has so much endlag that it isn't even safe on hit. I avoid it unless I really need it.
I want to incorporate down-b cancels into my gameplay, as a way to stay in midair longer than my opponent expects. However, I haven't practiced it very much, so I don't know how useful it really is.
Fair and bair are good. Not too hard to land, and the payoff is decent. You can choose to teleport behind them, or stay in place as they fly towards you. (If only you could b-reverse down-b, you could switch between fair and bair almost instantly...)
Dash attack is kind of deceptive. I'd feel bad about catching an opponent off-guard with it, because it gives no indication that the far hitbox stays around so long, or that it moves. A series of flashes showing the hitbox's motion would be nice. The move is fine other than that: it lets Zelda chase opponents offstage, and it sometimes sets up for dair.
The close hit of dtilt is weak, but I like the way the far hit sets up for dair. Even though the move doesn't let you teleport, there's about enough hitstun to run over there.
I love the Rivals of Ather-style recovery. It's annoying that you miss your chance if you walljump before your first up-b, but other than that, it's a great way to enhance an already good recovery.
Up-b bug: if you're touching a vertical wall when you teleport, and you're holding straight up, you'll go nowhere. (Exception: WarioWare's left wall; I don't know why.) If you hold towards the wall after walljumping, you'll slide towards it during the startup of up-b, and if you hit the wall before teleporting, you die. Sure you can angle away from the wall, but then you'll probably miss the ledge.
