If you are Aware, you are Conscious, that is it. Neuroscience is getting fairly close to working out how our brains make us aware of ourselves and our environments. Thus they are getting close to working out Consciousness. Neurotransmitter responses to our senses make us aware of our body. Visual, olfactory, tactile and audio senses make us aware of our immediate environments. The combination of these and our spacial senses such as our balance system give us the awareness of our spacial movements. All these are combined and computed in our brains to give us overall awareness of our own presence in time and space. Neurology is producing updated models for Consciousness all the time, some time soon, they may have an accurate model of human Consciousness.
Yes, of course. With enough time and energy and dedication we can unravel any mystery that has grounds in physicality presuming we create the instruments for it. If it is all directly connected to human wiring then there is no reason that this wiring cannot be unraveled and given understanding no different than the genetic code.
To clear up any misconceptions that may come from semantics I mean by consciousness simply that there is something being experienced at all. One does not need have any capacity to think about or reflect upon the experience or even any memory of any aspect of the experience. It could be as simple as say having a sensation of a thing (such as a color, a sound, or anything analogous) or not at any given moment of experience. By consciousness I do not mean self-awareness which is having awareness that one exists, thinks, feels, etc... I mean consciousness at its most basic and simple as being mere perception and nothing else necessary to count as consciousness.
The only truly observable thing from other people is their behavior. This is not to say mental phenomenon does not exist, but that for all we know everyone else could have no consciousness and are just acting as such because of the physics in their brain. The same goes for a person reporting a conscious experience and since we're not psychic odds are that sometimes a person falsely experiences an emotion which is then confirmed by everybody including psychiatrists because the person has also falsely (without knowing it is false) put on the correct facial expressions. If a large portion of people were confused about a feeling and all confirmed each other's experiences neuroscience might even falsely label a brain region as having to do with it when it really has to do with confusion of it.
For practical purposes we may find brain correlations with this or that feeling or this or that cognitive process (as expressed verbally or suggested by someone's behavior). But consciousness itself plays no functional role. It's a wonder why consciousness even exists at all. It isn't necessary to anything. We could've evolved not to have consciousness and to just be physical reactions doing everything exactly the same but with no consciousness of it.
Hence there is no way to ever truly know the physical basis of consciousness beyond any doubt. Searching for consciousness is a fool's errand. The only way we will ever discover it is with sophisticated mental gymnastics.
We need to simply accept that consciousness is based on the fact that we directly experience it. We can only ever know 100% for sure that our individual self is conscious and only guess that others are too, but assuming that they are just feels a lot more comfortable.