Aubrey works as a nickname for
Autumn Briana. If you're open to another spelling,
Aubrie would work as well, especially since it has Au- from
Autumn and has "bri" from
Briana. There's also Aubri, but it looks incomplete to me, so I'd either stick with
Aubrey or go with
Aubrie.
Aron or
Aaron nn
Ari - Yes, this works. I would just use
Ari even if I used
Aaron. Aari looks a bit off to me, but it works.
Schuyler nn
Sky - Yes, this definitely works. Schuy looks awkward to me. I think you'd be better off sticking with
Sky as a nickname for
Schuyler.