It's not bad and I'm not saying it is. I'm just referring to the image Arch
on which it's based seems to have (which isn't actually "bad" but
"difficult").
As for me, I tried Parabola but the first time I did I installed plasma 5 and
couldn't get Wi-Fi to work (which was also the case in Trisquel 7) and gave
up, but I'm pretty sure it would've had I installed, say, a shell straight
from its repos. Paerhaps I should come back to it some time. After all, I do
love pacman from my time with Manjaro......
Anyway, on an unrelated note, regarding installing an OS manually, I can and
do that with Trisquel: https://wiki.debian.org/Debootstrap (OK, some things
aren't quite fully manual over here but debootstrap is still pretty manual).
