I’ve moved to Arch like a month ago, first installed i3, I think you’ll only need xrandr and setup some hooks that set/reset xrandr on the screen plug/unplug, if you ALWAYS have two screens plugged in, you can execute xrandr on X startup and that’s all about it

Running rootless xorg recently got my Plasma to black screen after a min of launching sometimes, couldn’t switch to a tty (I could press the power button and it worked so ig only the GPU driver crashed or something) the problem most likely only aroused when I adjusted sddm settings from Plasma’s, which created a new sddm configuration file, removed rootless xorg config and it seems to have fixed it

I remember being able to create a persistent drive using Rufus and Linux Mint (Not the Debian edition though) , Rufus has a slider for creating a persistent drive when burning the iso, pretty sure you can find some guide online

Not sure about the security, but recently I’ve tried runit on a very old laptop with HDD and it took waaay much less to fully boot up than a clean Arch32 with systemd