I think that's why the majority of formal definitions of atheism have denial and/or lack.
Even conceptually, denial of god's existence is but a subset of a broader lack of belief. Someone who denies the existence of god necessarily doesn't believe in a god; however, someone who doesn't believe in god isn't necessarily making any statement about god's existence.
An agnostic lacks belief in god, not primarily because of lack of convincing evidence, but because he is persuaded that the existence or non-existence of god(s) is in principle unknowable. As a consequence, he is only sure that he has unsolvable doubts; when in doubt, he will generally opt for the most reliable knowledge available: empirical knowledge and reason. He may also take the apatheist position which is: the existence or not of deities is irrelevant.
Free-will is imprevisible and the future it's unknown by nature.
Not according to texts like Isaiah 46:10 and 1 Samuel 23:12, 1 John 3:20. The future is knowable to god. Again, special pleading.