What they sent out was a preliminary survey. Some of the items need more time to be produced so they're trying to get an idea of what people want to order. This isn't the 'official' survey, that will come later. They just want us to indicate what we plan to get. As far as I know you're allowed to change your mind.
Hellogre, I don't remember seeing anything about shipping... the amount listed under the pledge ($35, though some pledges were more or less) should be the correct amount. But you could send an email just to be sure. I'd send it through kickstarter. On the zombicide page at the right you'll see "project by coolminiornot" and under that "contact me." I'd use the contact me to see if anything else is required.
skolo, it's possible the surveys are going out in phases. With almost 9,000 backers the system may not be able to handle everyone at once. If you log in to kickstarter there might be a banner across the top of the page about the survey or a message from zombicide or something like that. If not I'd wait until Monday and if you still haven't heard anything then use the "contact me" link to see what's going on.