By no means did I mean that alchemy (or magic) would be anything but rare in these regions. I just meant that each region would have a mostly distinct supernatural practice. And of course, alchemists would be even fewer than the magicians.
Î'd like Ankoria's magic to include dark kinds of magic, but not be limited in that. Like Morcia's magic is very much defined by the contents of the Book of Morcia, Ankoria's magic is very much defined by the Book of Ankoria. The Sorcerer was neither inherently evil nor good. Thus, the magic he practiced in Ankoria wouldn't be just dark, though generally I suppose it'd be darker.
Based on the fact that curses would be important for Ankoria's magic, an idea is that it could be related with vocal magic, but that's not exactly a domain.
As for the Fire Desert/Peninsula (was it Alnnar?), how about they have a mix of magicians and alchemists?