Yeah it is definitely possible. Plus remember the maximum sell pressure created through that payout would be 1/104th of the payout every week. And that is if every single person powered down immediately, which of course wont happen.
Another real intriguing part of this whole experiment that I don't see people talking about too much is that both individuals and companies will want to buy STEEM to have steem power without going through the process of receiving it through participation. This is where STEEM can really be amazing in my opinion because what it would indicate is that getting your post upvoted on STEEM brings you exposure you cannot get elsewhere. So the interactions between all different types of participants will be fascinating to see.
RE: Are there any plans to allow us to exchange Steem for gift vouchers and other stuff