Solution 1:

Yes. When you run eb init it should only ask you for the things it doesn't know. Running it a second time should do nothing. Therefore I am presuming you are running eb init -i which forces all the questions. You can simply use eb init --region us-east-1 to switch. It shouldn't ask you any questions.

Solution 2:

When you run eb init, the EB CLI will generate .elasticbeanstalk/config.yml file inside working directory. The file format is something like:

branch-defaults:
  default:
    environment: Sample-Env
global:
  application_name: Example App
  default_ec2_keyname: SecretSSH-Key
  default_platform: 64bit Amazon Linux 2015.03 v2.0.0 running Docker 1.6.2
  default_region: us-east-1
  profile: null
  sc: null

You can modify default_region to another valid region.