@hhh one thing I forgot to mention:
Your tutorial worked fine on Jessie, but an annoyance during the partitioning was that every time a partition was edited, Thunar thought it was a new device and mounted it! You might add a note to go into Thunar's settings and temporarily disable auto-mounting of devices.
^ I had the same experience yesterday.
I did it once more but this time from my persistence LiveUSB (my #4 posted earlier). Due to my WebGL issues I made a second one to have a fresh BL environment, to see if I had made any changes in the one I currently use.
Anyway this time I nailed it in the first run, as I did not have the GParted issues I had earlier, just the auto-mount feature mentioned by johnraff.