thrifteee, I realize that some folks are constrained by their BIOS not supporting boot from USB but FWIW i prefer to never see an installer.
Live+persistence (and leave the HDD power cables disconnected) is how I usually roll.
consider removing the number of window managers that come by default
With the exception of a few iceWM themes which have many/large imagefiles, the wm -related files collectively occupy an insignificant amount of space.
You can verify my above claim by using the ncurses directory usage utility (if not already present, install its 120Kb "ncdu" package from debian repository) to quickly browse your usr / share / themes directories.