2. The 'origin' of a phenomenon refers the causes that generate the phenomenon. In math, as well as philosophy, the question is the origin of the answer. I'll give you an example. Where does the light from a lightbulb come from? Does it come from the bulb or does it come from the electricity itself? The bulb is simply the object which converts the electrical energy to EM radiation, not the origin of the light itself. Where does the electricity come from? The activities of the generator. So, mind is like light and consciousness is like an electrical wave.
3. Awareness of a fact means that you see a fact. It means that you receive the fact as it is. The dichotomy between experiential and physical things is illusory. It's simply that you experience the physical things from your own perspective, which is formulated by everything that has happened to you and everything you have done in the past - all of which were originated by activities as well. If we compare to a physical object, your consciousness is like the driver of a car (where your body is like the car), and when you are driving a car you can see through the windshield and you can feel feedback through the steering wheel. Hope this makes sense. This is not so easy to understand at first listen so please feel free to ask me continuous questions as I can help you to make your understanding more concrete.