Those classes are required to make the documentation looks great but they are not required in the context of the example.
If you’re introducing Kanbasu in an existing project, it’s recommended to prefix classes with a namespace. To do so, change the $namespace variable in the settings file.
It’s possible changing some settings break the build of your stylesheet. This is most probably because you entered a wrong value or changed the type of it. In fact some values are used to calculate others and therefor have to be set in a specific unit (pixels for example).