Here is a few updates for the udev.rules.gentoo from udev package.
I will summarise it briefly:
1) The last change you did to legacy tty's is wrong.
I say this because:
1a) The original devfs rules had both master and slave in /dev/pty:
nosferatu linux # grep devfs_name drivers/char/pty.c
pty_driver->devfs_name = "pty/m";
pty_slave_driver->devfs_name = "pty/s";
nosferatu linux #
1b) If you refer to '2.6.8.1-mm1 Tty problems?', you will see that
the /dev/tty/ directory our rules create, replaces this symlink:
nosferatu portage # ls -l /dev/tty
crw-rw-rw- 1 root tty 5, 0 Nov 14 17:06 /dev/tty
nosferatu portage #
which is used to determine the controlling tty.
2) Somebody added the /dev/cpu/microcode rule, but it was not run
as there was an older rule before that placing it in /dev/misc (which
is wrong). Just remove the first broken rule
3) Some form/tab cleanups. Reorder rules alphabetically according to
device class to make searching/editing easier.