generally like the idea as a step towards the right direction, but i think it might be better to not remove the current utility of vouchers by eliminating exchange-possibilites, but only add the exclusive items to the shop to bump up voucher demand - unsell i miss a major point in keeping the 'discount'-applicability of voucher-tokens...
clearly the better alternative to the last proposal, but not quite there yet imho, but there is always room for one more, right?