You will have to complement fCC curriculum with other resources! It is not only the DOM that is not included in the JS curriculum , for example in CSS the Box Model which is important, is also not included.
I am going through the Javascript certification and I am complementing it with other Udemy courses.
There is a lot of important stuff missing like deployment, Git and GitHub etc… The new v7.0 fCC curriculum is coming and hopefully things will change for better. http://forum.freecodecamp.org/t/help-us-build-version-7-0-of-the-freecodecamp-curriculum/263546