As noted earlier, your logic can track cleanly, but if it's based on faulty premises, it's worthless.
And why is the premise faulty?
I've got to admit that what I'm reading of the strong atheism position has a certain "true believer" ring to it, in that you start from the assumption that no God or Gods exist, and then work backwards to build a case.
Wrong. This is not what I or others do.
I do NOT hold “that no God or Gods exist” at all, so please don straw man my position. I say CLAIMS ABOUT SPECIFIC GODS leads me to conclude that that god cannot possibly exist. Thus my conclusion is simply the LOGICAL RAMIFICATION of the THEISTS CLAIMS.
But I class my self as a weak atheist, because when it comes to the concept of a god, a god that has not been anthropomorphised (e,g, the deist god), one cannot comment on whether such a ‘being’ or ‘thing’ exists since there is no evidence. Because of the lack of evidence, I lack belief in such a god, but I’m certainly willing to believe in this god given the evidence.
And in both cases, strong and weak atheism, I am more than willing to change my mind if I’m shown to be incorrect, or if new information becomes available. So your idea that I’m making an assumption then working backwards is simply wrong. I only state that a certain god cannot exist AFTER I’ve examined the theist’s claims (i.e. to see a contradiction), never regarding an unidentified god.
prefer the scientific skeptics approach: that with no assumptions either way,
Besides from the fact I make no assumptions, atheism is not an assumption)
This means you hold no
belief in a god, this you disbelieve in god, ergo this makes you an atheist, by definition!
and see what the evidence tells us.
I agree. We should abstain from belief in a god when there is no evidence to hold belief in one, thus abstaining from belief in god means you lack belief, ergo this makes you an atheist, by definition!
Proof of God A's existence: 'nuthing. Proof of God A's non-existence (?)... still nothing? Conclusion is God A almost certainly doesn't exist; about as much chance as the tooth fairy.
This describes atheism. God probably doesn’t exist, thus you choose not to believe one does, and thus this mean you lack belief in a god, ergo this makes you an atheist, by definition!
You’re a weak atheist; you just use a different word to describe the position: you misuse the word agnosticism. Nevertheless, the position is exactly the same.
But does God A definitely, beyond any shadow of a doubt, not exist? I just can't get there without a leap of faith (ironically enough).
You think atheism equates to being 100% sure that god does not exist?! This is simply wrong. It’s a misconception of atheism, created by theists, and it worked so well, even atheists fall for it, and thus don’t like to call themselves atheist, based on this error.
You seem to ignore the degree of belief/disbelief within theism and atheism respectively. There is more than one flavour of theism, just as there is more than one flavour of atheism. But in the end, atheism simply implies a lack of theism, nothing more. How one wishes to 'not believe' is immaterial to the word 'atheism' itself, just as how one holds to the Democratic Party positions is moot as to whether one is in fact a Democrat.