To "Must Obey":
I appreciate your references on agnosticism. Technically everyone is an agnostic, in the sense that nobody on earth can prove with 100% certainty the existence or lack thereof of a supreme being. The question then becomes one of belief, or lack thereof.
However, I do not agree with your definition of atheist that you posted:
If you allow for the possibility of God's existence but feel belief in God is not warranted because you don't consider there is enough evidence, then strictly speaking you are an agnostic, not a 'weak atheist'. An atheist is, by definition, some who feels the evidence clearly shows there is no God.
I'm a 'weak atheist' in that I simply don't believe there is a god. A 'strong atheist' fits your second definition, one who states (with a strong degree of certainty) that there is no God. While I believe the weight of the evidence is against the existence of a god (such as has been defined by various religions and dictionaries), I also know there's no air-tight 100% evidence either way. (As I mentioned before, the same could be said about Santa Claus. Perhaps he really does exist in a remote northern-hemisphere location.)
I wouldn't try to impose my definition on your belief system, so I hope you'll return the favor and not impose a definition on my unbelief system.