Hello, and thank you for this great community.
xset q | grep -A 1 Pointer
xset: unable to open display ""
Everything works fine except xset.
I have been trying to set mouse threshold with xset m 2/1 9
It shouldn't have anything to do with init systems. It sounds like you might be missing the DISPLAY variable in your environment for some reason and xorg can't find your display.
xset works only when Xorg is running, DISPLAY environment variable is set and the uid/gid of the process are allowed to access X server. For example, if you login as root in a terminal emulator under X session where you logged as a regular user, you normally won't be able to run X apps as root from that terminal emulator. If you execute (example):
$ xhost +si:localuser:root
from another terminal emulator as the user running the X session though, you will be able to.
Ran as non root user. Working, thank you.