"once we have committed a negative action, unless it is purified we will experience its consequences. We can't shirk the responsibility or try to make the karma disappear by justifying it. It doesn't work that way. Whoever commits an act will infallibly experience its results, whether positive or negative."
I say amen to this portion of the text because I can totally relate to this. It's so true that when I do something terrible, something terrible happens to me. It sucks, but karma gives everything bad some sort of justification. I also think it's true that we try to justify negative consequences but really, we're just suffering from our previous actions. While reading this part of the text, it felt like I was the one writing it because it holds so true to what I experience.Every time I do something bad, I know that it'll come back to me later on so I don't even bother trying to justify my negative consequences. I just know that some bad things happen because I have taken some negative action. I think karma gives us reason to believe that we can have some sort of control over our own lives, and I guess that's a good thing?

I dont really have anything I can argue against, however, I enjoyed the question and response section because those questions were similar to the ones I had about karma especially:
There are so many human beings and so much karma, how is it all arranged? How is it all kept track of? How does it all happen just right?
The more broad idea of karma is a little bit shaky, I think. How does all of this work? Basically, I feel that some things just have to happen, regardless of our own prior actions. Some things happen out of our control, and that's basically it.