Does this idea really seem stupid?

[Ben Davis]

I'm starting to get tired of this. Look, it doesn't matter how you spin it or how you analogise; atheism doesn't lead to action. Only the values that a person does hold can lead to actions, not the absence of ones that a person doesn't hold. This is obviously easy to grasp so why do you seem to have so much difficulty? You continually try to position atheism as a value system when it is not and can never be. I'm of the opinion that your misrepresentation is deliberate and arises because you're trying to reconcile an internal conflict (between the facts of atheism and your beliefs about atheism) in favour of your beliefs.

To point out the failures in your latest analogy:

I still maintain that belief or knowledge about agnosticism regarding a subject can motivate behaviour.

Misdefinition: you start by conflating knowledge and belief. As this premise is flawed, so will be every outcome of the resultant application.

My knowledge that I don't know about a topic for an exam can motivate me to study...

So we're focussing on knowledge for now? OK.
Nope. The absence of knowledge is not a motivator. Rather the need for knowledge is the motivator. You need to pass the exam therefore you need the knowledge. Even if there was no exam, the absence of knowledge would still not be the motivator; instead there would be a value which would trigger the action, for example the belief that one should know about the subject.

The knowledge that a person knows not either way about God can also influence someone too... e.g. I think that I will find out more or - I will explain to someone why I have no belief either way.

Nope. This is the same fail as above.

A clear example of this someone writing a post - she was aware of her agnosticism and she chose to explain this. Had she not been agnostic regarding the subject then she wouldn't explain why she was agnostic and had she not had knowledge about her agnosticism she wouldn't have done it either. The agnosticism and knowledge about it makes the person different to someone who is not agnostic and not aware of this.

Nope. The need to explain the agnosticism was the value that caused the explanation, not the agnosticism itself.

All I am saying is that if you are agnostic and aware of it then you will act differently had you not been.

Nope. This will only be true if you hold values which cause you to act on the agnosticism.

It seems obvious and outside of this forum I'm sure people could accept this but there seems to be a suspicion by some that admitting the above is falling into some evil plan I have...

Unlikely but not impossible. More likely is the fact that people recognise how wrong you are and therefore don't accept your proposition.

It seems silly to some to say that atheism has affected their lives and choose instead to refer to leaving religion or leaving belief in God which is just the same thing in different words...

Now you've suddenly switched from talking about knowledge to talking about belief. Presumably the result of your erroneous conflation of the topics in your flawed premise.

I don't think this undermines atheism - just undermines this idea that someone agnostic cannot be motivated by their agnosticism or their awareness of it....

Yes you do. You clearly think that because you're using it to try and undermine atheism. However all you're doing is undermining your straw-man definition therefore highlighting either your ignorance or your disingenuity.

Atheism can be a powerful and important thing in someone's life

No it can't. Rather the values which led someone to atheism will be the powerful & important things.