It lacks such termtypes as xterm-256color and xterm-88color for example.
it does have xterm-256color already
coreutils-5.2.1-r6 files on my machine are dated Jul 8 and /usr/portage/sys- apps/coreutils/files/DIR_COLORS file is dated Sep 13, so you must forgive me. Nevertheless, the colorizable termtype list is still incomplete - xterm-16color, xterm-88color, xterm-pcolor (is this one colorizable?) are not in the list (along with some oters, i think). BTW, debian does not have a xterm-256color terminfo file and the xterm-color is a 256-color one.
there are a ton of terminals which support colors, we dont add every single one for obvious reasons, just the ones people use if you actually use xterm-16color/xterm-88color/xterm-pcolor, i will add them, otherwise i wont bother
see above