dconf stores its configuration in the file ...
So backup that one. tweak-tool is about changing dconf settings.
- location to the wallpaper is in there. Not the wallpaper itself
- amount of viewports is in there
- size of launcher icons is in there
- color of launcher too
gsettings is the tool to change dconf. Example using wallpaper location:
gsettings set org.gnome.desktop.background picture-uri "file:///dir/to/wallpaper.jpg"
The "org.gnome.desktop.background" part is the structure inside dconf and picture-uri the parameter and the part in between "s the value.
Setting colors for background:
gsettings set org.gnome.desktop.background primary-color "#FFFFFF"
gsettings set org.gnome.desktop.background secondary-color "#FFFFFF"
gsettings set org.gnome.desktop.background color-shading-type "solid"
- FFFFFF being black
- shading-ype: SOLID, VERTICAL, HORIZONTAL are valid
Icon launcher size:
gsettings set org.compiz.unityshell:/org/compiz/profiles/unity/plugins/unityshell/ icon-size 32
This question How to dump all the manully altered gsettings keys? lists a method of dumping all settings changed by the user.