Maybe not. The fewer people they recruit, the less likely info will be spread.
Probably right. You could screw yourself big time on that. I wouldn't release information, but if I can't get in I want to know how they balance the Dawnguard against the vampire lords.
Unfortunately (or fortunately depending on how you look at it) I did not. There are a couple of scam type videos trying to convince you to download an application that generates Dawnguard beta keys but there's no way they'd work. We know that Bethesda picked people to send codes to and only plan to send a limited amount so an application that generates unlimited keys is absurd.
So we're looking at, what, another 10 people picked tomorrow or so?
Ah well. Not getting picked doesn't bother me so much, and it shouldn't bother you, too! Sure, you have to put down a bit of cash, but at least this way the final release will ideally have minimal issues and more enjoyable for the masses. If you'd been / will have been selected for the beta, you'd be expected to spend a considerable amount of time bug hunting in lieu of immersion and enjoyment of the content.
Assuming the people who got picked do their job and report the bugs.