Q: changing the apple store to different country

When you change the Apple ID region, you need to update your billing information with valid billing info e.g. credit card of the country you change the region to.

Change your iTunes Store country or region - Apple Support

Here's how you can create an Apple ID without the credit card. You can't create new Apple ID with the email address already used in a different account.

Create an iTunes Store, App Store, or iBooks Store account without a credit card or other payment method - Apple Suppor…

The iTunes Store in a country is intended for use only by that country's residents, and only while they are in the country. To use the iTunes Store in a country you need a credit card (or other card type if acceptable in a country) issued in that country, billed to an address in that country, and also be physically present in that country when using the store.  You are also restricted to waiting 90 days between country changes.

E.g., "The iTunes Service is available to you only in the United States, its territories, and possessions. You agree not to use or attempt to use the iTunes Service from outside these locations. Apple may use technologies to verify your compliance." - http://www.apple.com/legal/itunes/us/terms.html#SERVICE