On the syllabus where the list of lessons are, there is a green checkmark on the left side of the lesson name. Scroll over it, you should be able to click it, and that will uncheck that specific lesson.
Many people can give their two cents, but at the end of the day-- it really depends on you. Judging by your 7sage name...I think you may enhance your chances if you feel more optimistic and invigorated about putting in the effort to do well.
So, in weakening questions, the author has left his analysis/theory incomplete. With that incomplete theory, he goes on to make a strong conclusion. Hence, there is no reason to believe that the conclusion is supported by the theory.