USMLE exam is structured in a way that each thing that u do on it has a significance, since you are aware of these mistakes , you know that they do have some significance in the exam that is why you are asking them in first place, the answer to all the question is BIG yes.... all these are mistakes but how big are these would be subjective, cannot be commented in "one size fits all" way , so the moral of the story..... try not making them , since you are aware they are mistakes(i am assuming,many would not even know they are....)
regarding your assumption of a case on cs being straight forward(fracture)i would say you have high expectations, you will not have straight forward cases, you would have cases that have 5 differentials... great luck practicing and learning about CS....