They were a little coy on the topic of Titania's nature.
That aside, I wonder if the pixie zone will be set on the First. I'm leaning towards "no", because I think any such content mostly be dealt with via instanced content, however it's certainly the most ethereal and "otherwordly" zone so far. Which of course means nothing, per se. The architecture is reminiscent of Gridania, so they may tie it into that region's lore, maybe linking it to some cultural cross-pollination of some sort.
Now, since Dalmasca has been heavily hinted at in Orbonne, I think at least a few (1-2) zones will be there, and the Rak'tika Greatwood near it. If they stick with the pattern of 6 zones per expansion, and it's not on the First, I'm guessing at a zone in the southern provinces of Ilsabard. I wouldn't rule out Sharlayan yet, but I've a feeling they may reserve it and even the rest of Ilsabard (and maybe the moon if it plays no role for now) for 6.0, particularly as there's some hints at possible Ascian influence there - it'd be an obvious point of interest to them due to its heavy magic prowess and as the origin of most Scions. Fits in with the timing for the wrap up of the Zodiark/Hydaelyn arc.
Regarding G'raha, he makes the most sense to me for that character. I had thought Fordola, due to the tattoos and facial structure, but the body is too clearly male and the face is basically the same as he's got, plus the "tattoos" differ. The real questions will be who's in him (assuming there is but the robes suggest it is likely - the unusual colouration could be hinting at Elidibus), what caused the corruption and what role is he playing. We'll probably need to wait till 4.57 to get a better indicator.