Last I checked, you can't change an iOS app name once it's released. So there is indeed a massive issue down the road when you change the name.
Like Clynton says, doing your initial customer development with named apps, and transitioning to a generic name when the app launches is valid *however* you have to be very delicate about not losing users if your app does succeed. An update with a popup directing to install the new app is easy, however old users may not update. Best to prepare for this NOW, by having your app check a file on the server to see if it's valid or not, with a link for the new install on the server in XML. That way, users won't have to update to know that their app is invalid.
For non-region usage during beta period, having a notification when a user is outside the area is good but - well it depends on the app -- I could live in NY and be traveling. etc. Tough to think through these use cases. Great if out-of-the-area users could subscribe to get a push when the app is made available in their area. That, and email are great ways to build a customer list. However, if you're looking at it as a beta maybe best not to worry about it. When you re-release with a new name, you'll free yourself from ay past bad reviews on your store page.