I find it more useful to think of "consciousness" as a special model created by a subconscious human brain. Unlike other abstract models that a subconscious brain can create, such as a rock or a tree or a cat, the subconscious brain learns to associate details of this special model with certain physical perceptions that the subconscious brain receives (specifically, the physical perceptions that correspond with its own body, as opposed to physical perceptions that correspond to things that this system would model as not being part of its own body). By "subconscious human brain", I'm thinking of something like an embodied, complex neural network that receives sensory inputs of various kinds and sends signals to physically respond in various ways, but which doesn't have anything we would call "self-awareness" outside of this special model that's associated with the bodily physical perceptions.

I think this offers a nice balance between explaining the tremendous flexibility we have in understanding ourselves (by telling ourselves and others stories that change our models of ourselves) and explaining the tremendous limitations we have (because any model of a system within that same system is going to have to be significantly less complex if that system is going to do lots of other things, too). And I like that it doesn't suggest that we "aren't real"; instead, it suggests that at any given point in time, we're living, physical entities with subconscious minds that often contain self-referential models that tend to be very relevant to our actual physical living.

2) Assuming "[consciousness] is an illusion created because it was evolutionarily advantageous" is true, still how do those subjective sensations of existing and being aware of things - those qualia - how do they come about? How do these alleged consciousness-enabling genes that got selected into our genome create proteins that then create this qualia for us?