You wrote:
Is there a way to install Debian without any OS installed? From
all I've read, it seems like
MacOSX needs to be installed before Debian can be installed. Is
this still true?'
Only if you plan on multi-booting between OS X and Debian. If you're
only running Debian then mac-fdisk will partition your drive properly
for yaboot to work with it. I don't remember having this issue with
stable but the current testing builds have an issue where they only
create an 800 K New World boot partition when it actually needs to be
800 Mb.
-Gary