1. This was brought up because sometimes exam questions are tricky. The point I believe we were trying to make was that you should have those typical reasons a patient is experiencing their condition running in the back of your mind, but be ready to throw it out if the signs and symptoms you are gathering point to a certain root cause. Read: use your TCM diagnosis and treat what you see.
2. Hmm. I will have to try to find this questions, but I will give my reasons why I would use one or the other. LU10 clears Heat, and also Clears Heat when deficiency is present. LU5 clears Heat as well, but is used moreso when there is Phlegm-Heat in the Lung.