Storenvy encourages all of our users to sell internationally for a few reasons. By including the option of shipping "Everywhere Else" you are opening yourself to a much larger customer base. Most stores that have embraced international orders see an increase in sales.
The way the Storenvy marketplace is currently setup we do not have a way to block international customers from seeing stores that do not want to ship internationally.
The only way around this at this point is to set high shipping costs for the "Everywhere Else" shipping option to discourage international buyers, or to cover the additional costs of international shipping plus insurance for the package.