to be honest, I'm not an expert ;) but as far as I see, to install the language you have to start it with root permission so type in xterm

sudo gnome-language-selector

I'm not sure if you need, it you can just set your keyboard language with

setxkbmap fr

if you want to have it automatically for every bootup, just add it at end of

/home/test/.profile

I tried with ubuntu... but it was >20GB installation, so I changed to this smaller one, maybe later I try to use DSL again, its much smaller.

I'm curious about any results/experience, good ..... or bad :P