JBP is an academic and yes he is a bit hard to understand, that doesn't mean that it's nonsense, just that it will take more time to grasp his positions.
You can start with his university class in psycology: personality and transformation, I think it's the easiest starting point.
Then map of meaning.
I much prefer his lectures, live talks and podcast to the writings that are contrived and a bit overworked to my taste.
Is there a section I should watch?
What are the arguments against him?
I have watched all his university class and most of his talk, 100's of hours of material. I am very familiar with his positions.
But when I first heard about him I had a strong reaction against his positions and his complicated language. I was primed by CBC to hate him and I was trying to find a good reason. At the same time my cursiosity was activated so I watch him more and understood more and more.
So yes, he is not easy to understand, it take a lot of effort but it's been worth it for me.