Actually, 0-day refers to the time since public disclosure.

If that would be the case then we would have another term for the thing I just described, because that's the worst case scenario.

Anyhow, the Wikipedia article disagrees with you, too. Got any sources for your definition?

I think the recently added talks let you browse through various talks without having any topic in mind.

I agree with this being too long. When I see an ad which is a comic I instinctively expect it to be cheesy which is the impression I got with this. One panel might work if it is silly enough (SMBC style) or maybe 3 panels if you think up a good pun/punchline.