Is there a module that can make different registration forms for different roles during sign up? (ex. each Editor,Main User,Sub User role have different form)
There is :)
http://drupal.org/project/autoassignrole
to assign by path you will also need Content Profile:
http://drupal.org/project/content_profile
check out this tutorial on how to pull it off:
http://www.web-a-team.com/blog-post/user-registration-more-one-role