Congrats.WOO HOO!!! got it!
So what was my blunder?
- You tried to execute ck-launch-session(1) from the console, but that must fail, since it's designed to be run from within an already running X11 server. That's why it was complaining on the DISPLAY environ(7)ment variable not beeing set.
- Then there was a typo
startplasma=x11. - You misunderstood
lines that go intoa file as beeingcommands to typeon the console. Yes, in this case these are commands, but they need a certain setup/environment (running X11), to be executed in, and that execution is done by xinit(1) which reads the user's ~/.xinitrc - maybe more what don't recall now 'cause I'm dead beat.