Going in reverse order:
>Is consciousness non-binary?
I don't think so. Among people, the degree of conscious qualia does seem to vary a good bit. Would we really think some nigger in Africa with a literal room-temperature IQ has the same degree of inner life as someone like Francis Galton did? And we see the same thing across different species; some species show signs of consciousness (anon above mentioned the mirror test, for example), but likely don't possess the same degree of qualia and an "internal agent" that humans have. It's not obvious to me that increased intelligence necessarily implies developing consciousness, though. More on that below.
>Does consciousness affect anything?
The "philosophical zombie" thought experiment was always retarded. If an entity is identical to you, down to the atom, it can't possibly lack consciousness if you have it. I guess if you're inclined to a philosophically idealist or a theological view maybe you could disagree, but I see no way to make a copy of a conscious entity that somehow lacks this property.
But the most important question: who cares? I mentioned above that I don't think consciousness is a necessarily implication of intelligence, which I consider the more important property. Is there any reason to think for example that any silicon intelligence we manage to create will be conscious in the way we understand it? Why would it need to be, if it can behave intelligently? The conscious mind in people already mostly just pretends to be in charge, and makes up post-hoc rationalizations for things the body does autonomously anyway. The brain's job, from an evolutionary perspective, is to produce behavior, not to manipulate arbitrary information in an abstract way. Consciousness might well be an evolutionary fad that vanishes before too long.