Sensory overload. People with savant syndrom experience only partial sensory overload and many of them can´t live without help. The reduction of qualia helps us to focus on things that might be more important; for example what our conversational partner says instead of every other human being surrounding us within earshot in a crowded environment. If we would actively listen to everyone, our ears could hear, we would not stand one minute in a crowd without a nervous breakdown. But i think that everything is nevertheless part of our memory, even if we don´t have access.
(The function to forget is well known in psychology when it comes to traumatic experiences.)
Yes, why not. With technological brain enhancement this might be possible, someday.
It is just my definition of “unconscious”. You define “unconscious” as zero qualia and i define it as little qualia.
If qualia is a question of complexity. It seems very likely that at a certain level of complexity qualia emerges. But it is also possible that it is a completely new quality without the necessity of complexity…and that some spark…or particle is enough so that even simple organisms like amoeba are conscious if they possess this particle or whatever.