- debian/copyright:
I think that even if you choose CC0, you should indicate your name in
the Copyright: field as the rights holder/"Affirmer" of the license.
My understanding is that CC0 is not completely equivalent to code
already public domain. CC0 is the closest you can have to get your
work in the public domain, but since in some juridictions, you cannot be
sure that your copyright is completely waived, you still in this case
stay the copyright holder.
If noone else has an opinion on that, I would recommend to ask advice on
debian-legal@lists.debian.org.