Quote: "As such, to be a gnostic isn't to be absolutely sure you know something exists, but only to a degree of certainty, thus it's very possible to be a gnostic on either side."
From what you are saying, a person being gnostic or agnostic is still personal perspective, not social. So yes, a person can consider himself gnostic or agnostic depending on his own degree of faith. I would consider myself gnostic. Yet from a social perspective I can not prove that God exists. Nor can anyone else. Nor can anyone prove otherwise. So socially, everyone is agnostic.
I think the only thing that we really disagree on is whether it takes faith to have a lack-of-belief in something. Other than that, I think we are mostly saying the same thing using different words.
So, to that point, I would say that
you are right. It would take
no faith to have a
lack-of-belief in something. But, the only way you can have a lack-of-belief in something is if you are unaware of the subject.
If a person has never heard of the concept of God, how could he have belief/disbelief in it. There would be no way to measure faith, because it does not exist. In this scenario, I agree with you 100%
If a person does understand a concept, he either believes in it or not. THAT requires thought and a decision. A person has faith in his result even if he never considers the topic again in his life.
Applied to your point about the teapot orbiting saturn:
Before you mentioned it: I had no consideration of the subject / lack-of-belief / no faith existed.
After you mentioned it: Topic considered / un-belief / faith that I am correct.
Yet if someone did believe it, I could not prove them wrong!

a.k.a WOLF!