Couldn't help giving it a try. I have booted it to USB. I'm in the live. I don't like Chromium, but congrats for your configuration in it, just great ! I'll have to read more there, at the default welcome page. The personal bookmarks too... very good idea.
Criticism : you have kept the default icon set which is minimalist, but quite ugly. What about looking for new icons at box-look.org for instance ?
You have the tint2 bar which does not allow right-click menus. I suggest you edit the conf file and allow right-click menus on the tint2 panel. Same for the gtk2 theme : you could try to find one that would fit the style of your version better. I would think of one among the Equinox themes, even if it takes a little more space.
Space to gain:
# cd /
# find . -name "*.old"
./changes/etc/X11/xorg.conf.old
./changes/var/log/Xorg.0.log.old
./changes/var/log/dmesg.old
./union/boot/grub/device.map.old
./union/boot/grub/install.sh.old
./union/etc/X11/xorg.conf.old
./union/etc/blkid/blkid.tab.old
./union/etc/blkid.tab.old
./union/etc/fstab.old
./union/var/log/Xorg.0.log.old
./union/var/log/dmesg.old
./initrd/loopfs/boot/grub/device.map.old
./initrd/loopfs/boot/grub/install.sh.old
./initrd/loopfs/etc/X11/xorg.conf.old
./initrd/loopfs/etc/blkid/blkid.tab.old
./initrd/loopfs/etc/blkid.tab.old
./initrd/loopfs/etc/fstab.old
./initrd/loopfs/var/log/Xorg.0.log.old
./initrd/loopfs/var/log/dmesg.old
#
You can remove them all with one command line:
# find . -name "*.old" -exec rm {} \;(do not invoke such command before you make sure you don't need the files it will remove. This is why I do a simple "find" as the one before, then only I add the -exec command with options and arguments).
Then under /var/log you can remove all the files:
find . -type f -exec rm {} \;I don't remove the file prcys.log though, I put it aside and put it back after the command, otherwise the system happens to scream that it is missing, while rebooting.
There is no mc, and no bleachbit : how do you browse the fs to clean it ? I add it, now I can browse the directories (in a fast way)
Under $HOME/.config the following directories can be erased:
xfce4, Unless you configured a trick around the screenshooting with xfce4 ? viewnior, geany. Some app confs can be probably be removed from the .gconf directory. .gimp2.6 hidden directory can be removed... under .gnome2 too.
.gphoto settings can perhaps be removed and .qt directory, and .pki
I tested the screenshot shooter, that works ! I remove what I said about the xfce4 directory. If you assure me you need all the other hidden directories I pointed to, I'll also remove what I say.

(I hope a few ones can be removed though... )
You could uninstall geany and all it's depends that are not needed by other programs, and install xfe, or leafpad. If you install xfe then you could also remove viewnior as xfe is a suite with several little programs.
You got images left in the .thumbnail directory. You can remove the sub directories from there. They will be recreated when needed.
Under /etc/skel there are directories/files unneeded : .gimp2-6. Under /etc/skel/.config/rc.xml (my fault, it's one I forgot in Bonsai, but you can remove it from there).
You forgot files in /etc/skel/.local/share/Trash/info. In fact in .local/share you can keep the openbox directory and remove all the other ones. They are not needed and will be recreated when the distro will be in use.
In the home of root : /root the .local/share directory does not contain a wallpaper directory. No wallpaper for root ? I suggest you put the wallpaper in /usr/share/wallpaper, so it can be accessed from the user, the root and all future users, and you will gain a few k bytes as well. (This needs reconfiguring pcmanfm).
BTW, when copying the conf of pcmanfm, to /etc/skel/.config, copy the conf of libfm too : then you are sure all changes are there.
In /root/.local/share : you can leav openbox directory and it's sub-directory session and remove all the other directories with all their files.
There is a "dead.letter" as of September 14th under /
You might be able to avoid getting one by installing procmail, if I remember well.
All the directories under /root can be visited and cleaned out with the help of mc same as for the home of guest and the /etc/skel directory. There are files which are not needed there (.pki again... )
It will not make much weight gained probably, as a whole, but I guess it might help a little. Well at least removing the .gimp-2.6 directories in use home, root and /etc/skel should contribute to lower the size.

I will be happy to remaster it to French once it will be ready to go.

*Equinox : gtk-equinox-engine for Equinox theme, and gtk-theme-equinox which contain several variants from light to dark. You might want to try each one maybe with the help of lxappearance to ease the test process.
I will try to install it to hard drive tomorrow.
Have fun !
Mélodie