pkgmk won't send to our server, or anyone else's.

It simply creates the package on your machine. You will find it in /usr/ports/dir_you_launched/pkgmk_from.
To upload to our server is no accident. You need to contact us, generate a ssl key. Send the key via email. We install it on the server. Then you can log in and create a user folder. Upload your stuff. This is done with ftp/ssh2 (using gftp, cli, etc.).
Maybe I shouldn't of used "us" and "we". I'm not the guy to contact

The reason it asks for your name is there will be a bit of extra information in the slack-desc within the package. It tells who built it, machine/OS information, and what was passed to ./configure. So the next guy who comes along can replicate it, find out who made it, and what system it was built on. Handy stuff actually.
Does that shed some light on what's going on?
Edited to add examples:
This is what you see when checking out a package with slapt-get or gslapt.
Inkscape (SVG creator and editor)
Inkscape is an open source drawing tool with capabilities similar to
Illustrator, Freehand, CorelDraw that uses the W3C standard scalable
vector graphics format (SVG). Some supported SVG features include
basic shapes, paths, text, markers, clones, alpha blending, transforms
gradients, and grouping. In addition, Inkscape supports Creative Com-
mons meta-data, node-editing, layers, text-on-path, and SVG XML edit.
License: GPL
Author: Many, many authors. Please see docs.
Website: http://www.inkscape.org/
This info is contained in a file called slack-desc within the package. But you're only seeing part of it. The file actually has this (depending on the packagers preferences) in it. The packagers name, date, OS info and config options are at the bottom.
# HOW TO EDIT THIS FILE:
# The "handy ruler" below makes it easier to edit a package description. Line
# up the first '|' above the ':' following the base package name, and the '|'
# on the right side marks the last column you can put a character in. You must
# make exactly 11 lines for the formatting to be correct. It's also
# customary to leave one space after the ':'.
# |-----handy-ruler------------------------------------------------------|
inkscape: Inkscape (SVG creator and editor)
inkscape:
inkscape: Inkscape is an open source drawing tool with capabilities similar to
inkscape: Illustrator, Freehand, CorelDraw that uses the W3C standard scalable
inkscape: vector graphics format (SVG). Some supported SVG features include
inkscape: basic shapes, paths, text, markers, clones, alpha blending, transforms
inkscape: gradients, and grouping. In addition, Inkscape supports Creative Com-
inkscape: mons meta-data, node-editing, layers, text-on-path, and SVG XML edit.
inkscape: License: GPL
inkscape: Author: Many, many authors. Please see docs.
inkscape: Website: http://www.inkscape.org/
#----------------------------------------
BUILDDATE: Mon Jul 16 15:54:25 EDT 2007
PACKAGER: exeterdad
HOST: Linux 2.6.18.5 i686
DISTRO: Vector Linux 5.8 Standard 12-16-2006
CFLAGS: -O2 -march=i586 -mtune=i686
CONFIGURE: $ ./configure --prefix=/usr --mandir=/usr/man --disable-static --enable-lcms --enable-inkboard --program-prefix= --program-suffix= --with-included-gettext i486-slackware-linux