Works great out of the box. On ArchLinux at time of writing, SystemD automatically handles keeping the system from sleeping with the lid closed on the dock.

I use udev rules to trigger monitor reconfiguration (via an always-running script that runs in my user session, triggered via SIGUSR1).

/etc/udev/rules.d/81-thinkpad-dock.rules:

SUBSYSTEM=="usb", ACTION=="add", ENV{ID_VENDOR}=="17ef", ENV{ID_MODEL}=="100a", RUN+="/etc/thinkpad/thinkpad-dock"

/etc/udev/rules.d/81-thinkpad-undock.rules:

SUBSYSTEM=="usb", ACTION=="remove", ENV{PRODUCT}=="17ef/100a/0" RUN+="/etc/thinkpad/thinkpad-undock"

YMMV. Different udev versions handle USB events slightly differently.