i used the case book to study for my course final exam. i am not sure how usmle questions are, but i also agree that they may be too advanced. she only focuses on certain pathologies, such as COPD, restrictive lung dz, diabetes, metabolic acidosis vs alkalosis, osmotic diuresis, etc. the typical things that im sure you learned in lecture.
ide do multiple choice questions. its more of a review book than a book to study questions/cases from. kind of like a supplement or extra reading.