Yep, default-jre, default-jre-headless and gimp are installed. If I 
try to remove libsystemd0, it only requires to remove also gvfs, 
gvfs-daemons and gvfs-fuse, but, as explained before, xfce4 needs them. 
The funny thing is that now it doesn't ask me to remove policykit I 
probably made an error in my first trial.

     If you do a lot of sound manipulation, this is an area in which I 
can't help. Linux sound is a nightmare to me and I never found a 
sensible description of it all, so using pulseaudio by default because 
it mostly works out of the box. But there was a thread about it one or 
two weeks ago...

     Didier