Daas Torah In Halacha and Hashkafa

Is there a Torah idea called Daas Torah?
Can it override doctors?
Does the “Daas Torah” have to know the facts?
Can it override Shulchan Aruch?
Even if it’s not in contradiction with Halacha, must we listen to it ?
Is there such a thing as saying blanket statements without proofs that must be listened to?
Are we supposed to be using our heads?
If someone questions “Daas Torah” should he be explained the position or be branded a Kofer?
Do we believe in infallibility of Gedolim?
Can there be two “Daas Torah’s”?
Are two different people allowed to have different views, or is it my way or the highway?
How should we treat someone who disagrees with us?