I wouldn't say representative (don't use them as your only resource). They are great for the purpose of content review! That's what Chad's videos are all about. The quizzes keep you in check, to make sure you're actively watching the videos. Learn the concepts here, then move to destroyer to really master them.
Bootcamp is the closest you will come to real DAT questions, in terms of wording and difficulty.
the questions are meant to see if you generally understand the information. wouldn't really compare it to the DAT. if you are getting a lot of the questions wrong, you should probably re-watch that section.