Re: Because, um, yes, I was determined...
And with the sitting, Moon can probably do both but with varying degrees of comfort--the "kneeling" sort of sitting, would be a lot like a person sitting seiza. Fine if you're used to it, a hellish bitch that makes everything go numb if you're not (and oh, what a mental image--Moon with all those lower wings having gone to sleep. Moon would SO make Zack carry ta.) It would also probably give more leverage if Moon had to get up fast--the wings in the back are folded under the front ones, so he would basically get up and a launch from the force of all the wings pushing up at once.
The other would be more comfortable for long-term sitting, but also more dangerous in some ways because that is a lot more surface area to accidentally get stepped on. In as small as space as Zack's apartment is, Moon might be forced to sit in that seiza-esque style, and if ta wasn't used to it, it would be a bad time for everyone involved until ta did.
Aside from "screw physical limitations!", the nearest I can figure is magic--Safer-Sephiroth hovers, and uses the wings more for steering and giving push so it moves in the direction it wants to. Or, you know, the magic shrooms the character designers had before they set pen to paper.
And one of the great things about games: designs that go completely against the laws of nature and physics. I looked at the Safer-Sephiroth and went, "...why does it have a giant cloud around its waist, and how on EARTH does it go to the bathroom? Or even properly process food? It's kind of missing the place where, intestines go."
...The giant puffy cloud I am writing off as the feathers on the lower abdomen being puffed out in a threat display. And the rest, well, I drew Moon with enough abdomen for necessary internal organs. I'm sure they're there on the original, just hidden by the giant puffy cloud threat display feathers. >XD
And since Moon is still kind of young, I wonder if those feathers would still be mainly soft, fluffy down.