Your described course of action with regards to all of this, seems like a very logical and smart path to take. I understand how many drugs work, and what many are for. I understand many things better than my physicians and we often spend time in my checkups with me lecturing them on mechanism of one thing or another. Yet still, I don't decide what drugs I need or how much I need, I leave that to them and always try their prescribed course of action.
I don't think there should be drug advertisements at all. Leave that to physicians. The average person lacks the training to effectively self diagnose.
Pharmacists have also told me that it is common for them to have to fix errors doctors have made in their prescriptions. It is important to have a competent pharmacist.
Indeed they are essential to check for drug interactions with other medications already being taken.