Basically it's incredibly grunt-work-based. I've manually logged everything into a spreadsheet. I'll then hand that off to BackerKit, who will import that same as they have for the main kickstarter pledges.
From then on we'll manage fulfillment and so forth for everyone through BackerKit (which is way more advanced functionally than Kickstarter itself, hence its wide use).
Because it's kind of a pain for the backerkit folks (and they made that clear), I'll have to take down the paypal page after I send them the spreadsheet for the first time. It's then all based on Stripe on their end until we hit EA on Steam and then people can buy it like normal then on Steam or Humble or whatever.
If there's someone who wants an Alpha key but only has paypal and wants to do that after the paypal page is taken down, then we'll have to handle them as a one-off. BackerKit does support paypal if you upgrade your plan to a higher one, but it would cost us an extra $970, which we wouldn't earn back in paypal pledges by any stretch of the imagination.
Complicated! Hopefully very simple on your end, though: once in backerkit you'll get an email with the survey and so on, and then later emails with your keys and other rewards, and that should be that.