The acceptation and production modes are meant to be used for the server(s) where the finished application will actually run.These servers are typically not directly available but managed by the system administration department. A formal procedure is usually in place to manage the transitions from test to acceptation and acceptation to production. Therefore, simply deploying and running from within the Modeler is not an option.
Edit: it is correct that you cannot change the administrator password for the acceptance and production modes. Those passwords are stored in configuration files on the server(s) and the passwords entered in the Modeler are not used. That holds for all settings in the acceptance and production tabs and that is why they are disabled completely. They are still there for the sake of reference but they will be gone in the next version of our technology.