customize address forms

It'd be nice to be able to customize address forms. Some countries have different requirements. e.g. in New Zealand, most people don't know their post code, and it is not required for a package to arrive. Nor is Province. Terms such as 'state' and 'zip code' are not used here. A client's store only ships to NZ, so it'd be nice to be able to disable the country selector in address forms.

It'd be great to be able to change the form in the following ways:
- order of the fields
- whether each field is required
- visibility of each field
- label for each field
- whether he field is text or option selector
- if option then:
- drop down or radio
- default value of each field
- (add custom fields)?

These forms could be set globally and / or, for each user type:
- ec_anon user
- user registering/registered through checkout
- user already registered through drupal